# Geographic Areas Reference Manual/Chapter 8

​Chapter 8
All counties and statistically equivalent entities consist of one or more geographic units that the Bureau of the Census recognizes as county subdivisions. The two major types of county subdivisions are minor civil divisions (MCDs) and census county divisions (CCDs). A State has either MCDs or their statistical equivalents, or CCDs; it cannot contain both.
Minor civil divisions are the primary subcounty governmental or administrative units; they have legal boundaries and names as well as governmental functions or administrative purposes specified by State law. The most familiar types of MCDs are towns and townships, but there are many others (see Table 8-1). In some situations, the Census Bureau must complete the coverage of subcounty units by creating additional entities called unorganized territories (UTs) that it treats as being statistically equivalent to MCDs. The Census Bureau has established UTs in certain MCD States to account for the part or parts of a county that are not within any MCD or MCD equivalent. As of 1994, unorganized territories exist in nine States: Arkansas, Iowa, Indiana, Louisiana, Maine, Minnesota, North Carolina, North Dakota, and South Dakota. The Census Bureau recognizes MCDs and MCD equivalents as the county subdivisions of 28 States and the District of Columbia (see Figure 8-1).
Census county divisions are the statistical entities established cooperatively by the Census Bureau and officials of State and local governments in the 21 States where MCDs either do not exist or are unsatisfactory for the collection, presentation, and analysis of census statistics. They are designed to represent community areas focused on trading centers or, in some instances, major land use areas. They have visible, permanent, and easily described boundaries.
In the State of Alaska, which has no counties and no MCDs, the Census Bureau and State officials have established census subareas (CSAs) as the statistical equivalents of MCDs. These are subdivisions of the boroughs ​(legal entities) and census areas (statistical entities), both of which serve as the geographic equivalents of counties in Alaska. Although CSAs are similar to CCDs, there are enough differences to warrant treating them as a separate type of county subdivision.
The decennial censuses of population and housing identify and present data for all types of county subdivisions in every State (see Table 8-2). Certain types of MCDs figure in the population estimates programs, the Census of Governments, and, on a selective basis, the economic censuses. This chapter discusses the county subdivisions of the United States; for information on similar geographic entities in Puerto Rico and the Outlying Areas, see Chapter 7.
The decennial population censuses always have sought to identify county subdivisions as a primary geographic entity. The first census (1790) reported population counts for MCDs (towns, townships, and other units of local government), and this practice continued throughout subsequent censuses. For States in which local governmental units did not exist below the county level, various administrative units or other area designations were used, such as companies, districts, hundreds, remainder of county, and eastern (or western) portion of county. Although this chapter does not trace the history of such alternate and short-lived entities in detail, the final section of this chapter provides some background information about the different kinds of MCDs used for the 1990 decennial census.
Starting with the 1950 census, there have been four significant developments in the Census Bureau’s treatment of county subdivisions: (1) the replacement of MCDs with CCDs in 21 States, (2) the establishment of the UT as a standard geographic entity in 9 States, (3) the subdivision of Alaska into CSAs, and (4) the establishment of the Boundary and Annexation Survey (BAS) program.
​Table 8-1. Type and Number of County Subdivisions in 1990
| Townships | 18,154 |
| Census County Divisions | 5,581 |
| Incorporated Places | 4,533 |
| Towns | 3,608 |
| Election Precincts | 948 |
| Magisterial Districts | 735 |
| Parish Governing Authority Districts | 627 |
| Supervisors’ Districts | 410 |
| Unorganized Territories | 282 |
| Election Districts | 276 |
| Census Subareas | 40 |
| Plantations | 36 |
| Assessment Districts | 21 |
| American Indian Reservations | 7 |
| Grants | 9 |
| Purchases | 6 |
| Boroughs | 5 |
| Gores | 4 |
| Locations | 4 |
| Pseudo County Subdivision | 1 |
| Road District | 1 |
| Total County Subdivisions: | 35,298 |
* ↑ Entities established for statistical reporting purposes only.
* ↑ This total includes only those incorporated places that are governmentally independent entities. For details, refer to the subsections “Treatment of MCDs and Places in the Data Tables,” “Criteria for MCD Equivalents,” “Places,” and to Tables 8-2, 8-3, and 8-4.
* ↑ Only in a few instances are American Indian reservations coextensive with an MCD (see Table 8-2).
| Alabama | Census County Division | 390 |
| Alaska | Census Subarea | 40 |
| Arizona | Census County Division | 78 |
| Arkansas | Township | 1333 |
| Arkansas | Unorganized Territory | 2 |
| California | Census County Division | 386 |
| Colorado | Census County Division | 208 |
| Connecticut | Town | 169 |
| Delaware | Census County Division | 27 |
| District of Columbia | Incorporated Place (city) | 1 |
| Florida | Census County Division | 293 |
| Georgia | Census County Division | 581 |
| Hawaii | Census County Division | 44 |
| Idaho | Census County Division | 170 |
| lIlinois | Township | 1434 |
| lIlinois | Election Precinct | 243 |
| lIlinois | Incorporated Place (city) | 2 |
| Indiana | Township | 1008 |
| Iowa | Township | 1602 |
| Iowa | Incorporated Place (city) | 53 |
| Iowa | Unorganized Territory | 1 |
| Kansas | Township | 1414 |
| Kansas | Incorporated Place (city) | 129 |
| Kansas | Unorganized Territory | 2 |
| Kentucky | Census County Division | 475 |
| Louisiana | Parish Governing Authority District | 627 |
| Louisiana | Incorporated Place (city) | 1 |
| Louisiana | Unorganized Territory | 1 |
| Maine | Town | 433 |
| Maine | Plantation | 36 |
| Maine | Unorganized Territory | 35 |
| Maine | Incorporated Place (city) | 22 |
| Maine | American Indian Reservation | 3 |
| Maine | Gore | 1 ​ |
| Maryland | Election District | 276 |
| Maryland | Assessment District | 21 |
| Maryland | Incorporated Place (city) | 1 |
| Massachusetts | Town | 312 |
| Massachusetts | Incorporated Place (city) | 39 |
| Michigan | Township | 1242 |
| Michigan | Incorporated Place (city) | 283 |
| Minnesota | Township | 1803 |
| Minnesota | Incorporated Place (city) | 880 |
| Minnesota | Unorganized Territory | 59 |
| Mississippi | Supervisors’ District | 410 |
| Missouri | Township | 1367 |
| Missouri | Incorporated Place (city) | 1 |
| Montana | Census County Division | 193 |
| Nebraska | Election Precinct | 705 |
| Nebraska | Township | 469 |
| Nebraska | Incorporated Place (city) | 81 |
| Nevada | Census County Division | 67 |
| New Hampshire | Town | 222 |
| New Hampshire | Incorporated Place (city) | 13 |
| New Hampshire | Grant | 8 |
| New Hampshire | Purchase | 6 |
| New Hampshire | Township | 6 |
| New Hampshire | Location | 4 |
| New Jersey | Incorporated Place (total) | 320 |
| New Jersey | Borough | 250 |
| New Jersey | City | 52 |
| New Jersey | Town | 15 |
| New Jersey | Village | 3 |
| New Jersey | Township | 247 |
| New Mexico | Census County Division | 131 |
| New York | Town | 932 |
| New York | Incorporated Place (city) | 62 |
| New York | American Indian Reservation | 14 |
| New York | Borough | 5 |
| North Carolina | Township | 1037 |
| North Carolina | Unorganized Territory | 3 |
| North Dakota | Township | 1352 |
| North Dakota | Incorporated Place (city) | 373 |
| North Dakota | Unorganized Territory | 81 ​ |
| Ohio | Township | 1318 |
| Ohio | Incorporated Place (total) | 235 |
| Ohio | City | 171 |
| Ohio | Village | 64 |
| Oklahoma | Census County Division | 302 |
| Oregon | Census County Division | 211 |
| Pennsylvania | Township | 1549 |
| Pennsylvania | Incorporated Place (total) | 1034 |
| Pennsylvania | Borough | 977 |
| Pennsylvania | City | 56 |
| Pennsylvania | Town | 1 |
| Pennsylvania | Road District | 1 |
| Rhode Island | Town | 31 |
| Rhode Island | Incorporated Place (city) | 8 |
| South Carolina | Census County Division | 294 |
| South Dakota | Township | 973 |
| South Dakota | Incorporated Place (total) | 318 |
| South Dakota | City | 162 |
| South Dakota | Town | 155 |
| South Dakota | Village | 1 |
| South Dakota | Unorganized Territory | 98 |
| Tennessee | Census County Division | 462 |
| Texas | Census County Division | 863 |
| Utah | Census County Division | 90 |
| Vermont | Town | 242 |
| Vermont | Incorporated Place (city) | 9 |
| Vermont | Gore | 3 |
| Vermont | Grant | 1 |
| Virginia | Magisterial District | 458 |
| Virginia | Incorporated Place (city) | 41 |
| Virginia | Pseudo County Subdivision | 1 |
| Washington | Census County Division | 245 |
| West Virginia | Magisterial District | 277 |
| Wisconsin | Town | 1267 |
| Wisconsin | Incorporated Place (total) | 627 |
| Wisconsin | Village | 417 |
| Wisconsin | City | 210 |
| Wyoming | Census County Division | 71 |
Many States in the southern and western parts of the United States had few or no subcounty governmental units that could serve as an adequate geographic framework for census purposes. The MCDs in those States frequently proved difficult to enumerate because their boundaries and names were not well known locally or were subject to frequent change. Also, these MCDs presented problems in the data tabulations because they often divided incorporated places into many component parts. This cluttered the census tables with superfluous lines of data, many with very small populations that were not meaningful to data users or that yielded statistically unreliable data from the questions asked of only a sample of households. In addition, most data users found these MCDs unsatisfactory for purposes of statistical analysis because of frequent name changes and boundary shifts that resulted in a lack of geographic comparability. These changes made it difficult—or impossible—to use these MCDs as a stable spatial unit for historical comparisons.
Some counties in certain MCD States contain territory, usually somewhat remote and sparsely populated, that is not part of any MCD. For States in which the township and range system of land survey existed, these areas usually were included in some governmentally nonfunctioning survey township. In other States, these expanses of territory often were unnamed, and identified in the census data tables as unorganized area, unsurveyed area, or balance of county.
These geographic areas posed problems in both the collection and the presentation of decennial census data. Enumerators had a hard time locating the boundaries of survey townships; moreover, the survey townships often were very numerous and usually too small in population to provide statistically reliable data from the questions asked on a sample basis. Names such as Township 69 and Range 21, or Fractional Township 70 and Range 18 cluttered the statistical tables and associated maps, and proved confusing to data users. In other situations, the unorganized area consisted of several discontiguous pieces of unnamed territory which posed problems in the decennial census data presentations. In 1970, the Census Bureau simplified its coverage of these areas by establishing a standard geographic entity, the UT, for data presentation purposes. By establishing UTs, the Census Bureau was able to simplify the nomenclature and improve the geographic pattern by using a smaller, more manageable number of subcounty entities.
In its statistical presentations, the Census Bureau has used a variety of administrative and governmental units to subdivide Alaska. The present set of primary and secondary geographic subdivisions dates from the 1970 census when the Census Bureau and State officials cooperatively established census divisions and census subdivisions as the county and subcounty equivalent geographic entities. In those parts of Alaska covered by boroughs (large-area governmental units with functions and powers similar to counties in the coterminous 48 States), the census divisions usually were the same as the boroughs, although in a few instances they included adjacent military ​reservations. In the remainder of the State, the unorganized borough (the legal term for the area outside of any borough), the Census Bureau and State officials delineated census subdivisions to generally follow the boundaries of the State’s election districts. The census subdivision level served to identify boroughs and military reservations within census divisions. One of the census divisions derived from the unorganized borough was divided into two portions, each a census subdivision.
The Census Bureau and State officials adjusted the census division and census subdivision boundaries for the 1980 census. The borough-based census divisions were then referred to as boroughs, the remaining census divisions were renamed census areas, and all the census subdivisions were renamed census subareas. Many of the former census divisions were split or merged to conform to the boundaries of the recently established Alaska Native Regional Corporations (ANRCs). In some cases the boroughs and census areas were subdivided into census subareas by using the boundaries of the ANRCs, significant military reservations, and the 1970 census divisions. Most of the 1980 CSAs remained unchanged for 1990, except for those in parts of the State in which new boroughs and new census areas had been established.
In 1972, the Census Bureau initiated the Boundary and Annexation Survey (BAS) program. The BAS, repeated periodically, collects information about the legal characteristics, territories annexed or detached, and boundaries of all counties, MCDs, and incorporated places. The BAS program supplanted the previous practice of obtaining local maps showing the legal boundaries, either at the time of the actual enumeration, or shortly before the decennial census date. The BAS, a more systematic, continuing effort, has brought major improvements in the accuracy and timeliness of the Census Bureau’s inventory of geographic entities. It is now the standard source for ascertaining the existence and legal status of governmental units such as counties, incorporated places, and MCDs; it also identifies any changes in their names or boundaries. By means of the BAS, the Census Bureau can detect important developments, such as MCD boundary changes, the formation of new ​MCDs, the merger or consolidation of MCDs, and the disorganization (dissolution) of MCDs. For further information on the BAS, refer to Chapter 9, “Places.”
The Census Bureau attempts to maintain a set of county subdivisions that are, geographically speaking, relatively stable from one decennial census to another. In the 28 MCD States, the Census Bureau always revises the county subdivisions to reflect boundary or status changes resulting from legal or administrative actions. At the time of each BAS, the Census Bureau considers local recommendations about the boundaries and areas of any UTs that might be required to complete the MCD coverage of a State.
The establishment of CCDs in a State is a cooperative effort between the Census Bureau and State authorities. The first step usually is an expression of interest on the part of State officials and local data users, followed by consultations to determine if there are legal or constitutional requirements for maintaining the existing MCDs. The Census Bureau does not compel a State to replace its MCDs with CCDs; the decision always rests with the appropriate State officials and ultimately with the State governor.
In the 28 MCD States, the Census Bureau uses the existing legal entities as the standard county subdivision framework. To do this, it selects the type of subcounty unit—or in a few instances, more than one type—that (1) is a legally defined entity, (2) provides complete or nearly complete geographic coverage, and (3) has geographic stability.
Many MCDs function as general-purpose local governments; that is, they provide a wide range of public services to the inhabitants of a specific subcounty area. Almost all of these local governments are active and functioning; however, others may have an inactive status as governmental units, yet still constitute legal entities. In States that have no local governmental units below the county ​level, or where incorporated places are the only form of local government, the Census Bureau uses the most important and best known type of administrative subdivision; for example, election precincts or magisterial districts. Table 8-3 provides further detail about the governmental status of county subdivisions in the 28 MCD States.
Table 8-3. Governmental Status of Minor Civil Divisions in 1990
| Arkansas | The townships are nonfunctioning geographic subdivisions of counties and are not governments. |
| Connecticut | Of the 169 towns, 149 are actively functioning governmental units. The remaining 20 towns are areally coextensive with a single incorporated place; 19 towns are coextensive with a city and one town is coextensive with a borough. In each of these 20 instances, the town and city governments are consolidated, and the Census Bureau classifies the incorporated place government as the active government. |
| Illinois | Of the 1,434 townships, all but one are actively functioning governmental units. The exception is Cicero township coextensive with the city of Cicero, which performs the functions of the township as well. The election precincts are nonfunctioning geographic subdivisions of the county used in conducting elections and are not governments. |
| Indiana | All townships are actively functioning governmental units. |
| Iowa | Through an agreement between the State of Iowa and the Census Bureau, all townships are classified as nonfunctioning geographic subdivisions of the county and are not governments. Iowa townships can, and some do, perform a limited governmental function, but the township officials for the most part are administrative adjuncts of the county government. |
| Kansas | Of the 1,602 townships, 1,543 are actively functioning governmental units. The remaining 59 townships are inactive, but have the ability to activate and perform governmental functions. |
| Louisiana | The parish governing authority districts in Louisiana are nonfunctioning geographic subdivisions of the county used in conducting elections and are not governments. |
| Maine | All 433 towns and 36 plantations are actively functioning governmental units. The single gore is a nonfunctioning geographic subdivision of the county and not a government. The three American Indian reservations are functioning tribal governments; the MCD reservations are not counted as governments. ​ |
| Maryland | The election and assessment districts are nonfunctioning geographic subdivisions of the county used in conducting elections and levying taxes, respectively, and are not governments. |
| Massachusetts | All towns are actively functioning governmental units. |
| Michigan | All townships are actively functioning governmental units. |
| Minnesota | All townships are actively functioning governmental units. |
| Mississippi | The supervisors’ districts are nonfunctioning geographic subdivisions of the county that are districts from which voters elect county supervisors and are not governments. |
| Missouri | There are 23 counties containing 324 actively functioning townships. In the remaining 91 counties, there are 1,043 townships which are nonfunctioning geographic subdivisions of counties and are not governments. |
| Nebraska | Of the 469 townships, 453 are actively functioning governmental units. The remaining 16 townships are inactive, but have the ability to activate and perform governmental functions. The election precincts are nonfunctioning geographic subdivisions of the county used in conducting elections and are not governments. |
| New Hampshire | Of the 222 towns, all but one are actively functioning governmental units. The remaining town, Livermore in Grafton County, is inactive, but it has the ability to activate and perform governmental functions. The grants, locations, and purchases are nonfunctioning geographic subdivisions of the county and are not governments. |
| New Jersey | All townships are actively functioning governmental units. |
| New York | Of the 932 towns, all but three are actively functioning governmental units. Each of the remaining three towns is areally coextensive with a single incorporated village (East Rochester in Monroe County, and Mount Kisco and Scarsdale in Westchester County). In each of these instances, the town and village governments are consolidated, and the Census Bureau classifies the incorporated place government as the active government. The three American Indian reservations are functioning tribal governments; the MCD reservations are not counted as governments. The five boroughs are classified as nonfunctioning geographic areas at the MCD level and not as governments. ​ |
| North Carolina | The townships are nonfunctioning geographic subdivisions of counties and are not governments. |
| North Dakota | Of the 1,352 townships, all but one are actively functioning governmental units. The remaining township, Fargo in Cass County, is inactive, but it has the ability to activate and perform governmental functions. |
| Ohio | Of the 1,318 townships, all but one are actively functioning governmental units. The remaining township, Wayne in Montgomery County, is inactive, but it has the ability to activate and perform governmental functions. |
| Pennsylvania | Of the 1,549 townships, all but one are actively functioning governmental units. The remaining township, Cold Spring in Lebanon County, is inactive, but it has the ability to activate and perform governmental functions. The single road district, East Fork in Potter County, also is an actively functioning government. |
| Rhode Island | All towns are actively functioning governmental units. |
| South Dakota | All townships are actively functioning governmental units. |
| Vermont | Of the 242 towns, all but five are actively functioning governmental units. The five remaining towns (Glastenbury in Bennington County, Averill, Ferdinand, and Lewis in Essex County, and Somerset in Windham County) are inactive, but they have the ability to activate and perform governmental functions. The gores and grant are nonfunctioning geographic subdivisions of the county and are not governments. |
| Virginia | The magisterial districts are nonfunctioning geographic subdivisions of the county used in conducting elections or recording land ownership, and are not governments. Arlington County is not divided into magisterial districts; the Census Bureau assigns the area of the county to a single, nongovernmental pseudo-MCD representing the county. |
| West Virginia | The magisterial districts are nonfunctioning geographic subdivisions of the county from which voters elect county commissioners and members of the school boards. |
| Wisconsin | Of the 1,267 towns, all but one are actively functioning governmental units. The remaining town, Menominee, is coextensive with Menominee County. The town and county governments are consolidated, and the Census Bureau classifies the county as the active government. |
The Census Bureau requires that the MCDs encompass as much of the geographic area of a State as possible. Where the MCD coverage is incomplete, the Census Bureau attempts to supplement the MCD coverage with an entity or entities that are MCD equivalents. There are a few States where the Census Bureau must use more than one type of MCD; for example, in Illinois it uses 1,434 townships and 243 election precincts (see Table 8-2). In the portions of MCD States where no MCDs exist, the Census Bureau establishes UTs (see the “Unorganized Territories” section in this chapter).
The Census Bureau prefers that the MCDs in a State remain relatively stable from one decennial census to another, with only minor changes in their boundaries and areas. If there are massive or widespread changes, the geographic pattern of subcounty governmental units or administrative subdivisions is disrupted and the historical comparability of the data is impaired. When that happens, the Census Bureau may encourage the appropriate State officials to consider replacing the MCDs with CCDs.
The Census Bureau recognizes two types of geographic entities that, for statistical purposes, are equivalent to MCDs—independent incorporated places and UTs. Although these two classes of entities are not, strictly speaking, MCDs, the Census Bureau treats them as MCDs in order to include all of a State’s population and land area within the county subdivision level for data presentation purposes. In addition, there are anomalous situations in which miscellaneous types of geographic entities are equivalent to MCDs (see the “Miscellaneous Entities” section in this chapter).
These are incorporated places with governments that function independently from the jurisdiction of the surrounding MCD or MCDs. They do not receive governmental services from any MCD, except when they undertake to contract for such services. Their inhabitants do not pay taxes to any MCD, nor do they vote ​in any MCD elections. The independent incorporated places in a State constitute a separate type of county subdivision apart from its MCDs. Of the 28 MCD States, there are 20 with such MCD equivalents. At the time of the 1990 census, only 19 States had independent incorporated places. An additional State, North Carolina, now has independent incorporated places as well. Usually these independent incorporated places are cities; however, in some States they also are boroughs, towns, and villages (see Table 8-2).
Also independent of MCDs are those incorporated places that are independent of any county; the Census Bureau refers to these as independent cities. The Census Bureau treats the entire independent city as a single entity that is equivalent to both a county and an MCD. Virginia has 41 independent cities; Maryland and Missouri each have 1 (see Chapter 4, “States, Counties, and Statistically Equivalent Entities,” for details).
Some counties in nine MCD States (Arkansas, Indiana, Iowa, Louisiana, Maine, Minnesota, North Carolina, North Dakota, and South Dakota) contain unorganized areas, areas that never had, or no longer possess, any governmental or administrative organization similar to the other MCDs in that State. Such areas have no legal name, legal status, or legal boundaries (except where bounded by MCD limits or a county line); the county and/or State provides the governmental functions for their residents.
The Census Bureau uses the term unorganized territory to identify such areas, and has developed a standard approach to simplify the presentation of data for them in the tabulations from the decennial censuses. The Census Bureau delineates each contiguous unorganized area as at least one UT. Larger areas are divided into more than one UT using physical features as boundaries. Each separate area thus is recognized as a UT, and may be named for a former MCD, a large settlement, or a physical feature—depending on which name best describes the area. In counties with several geographically discontiguous pieces of unorganized area, each piece is given an easily recognizable name usually based on its location within ​the county; for example, Central Hancock unorg. and East Hancock unorg. These measures make it easier for data users to refer to these areas on maps and in the Census Bureau’s data presentations.
The Census Bureau classifies a few other geographic entities as MCD equivalents. It treats the District of Columbia as an entity statistically equivalent to a State, and as a single county equivalent with the same name. The District of Columbia also is coextensive with the incorporated place of Washington city. The Census Bureau uses a single MCD, also called Washington, to represent the same geographic area recognized as the city, county equivalent, and State equivalent. Arlington County, Virginia, represents a similar situation, where no MCD exists within the county area. The Census Bureau recognizes a pseudo MCD to cover the entire county-level area and gives it the same name as the county.
In the TIGER data base, there exists water area within the Atlantic Ocean and Great Lakes that is not assigned to any land MCD. The Census Bureau assigns these waters to an MCD entity identified by a code of 000, and includes the measurement figures for them as part of the county total. No other data are published for these entities.
The purpose of CCDs is to provide a set of subcounty units that (1) have community orientation; (2) have visible, stable boundaries; (3) conform to groupings of census tracts or block numbering areas (BNAs); and (4) have a recognizable name.
Each CCD should be focused on one or more communities or places, and take in the additional surrounding territory that is served by these in some fashion. The definition of community takes into account factors such as production, marketing, consumption, and the integrating factor of local institutions. This criterion is an application of the functional integration principle that the Census Bureau uses to create some geographic statistical entities (for details, refer to Chapter 2).
​The place on which a CCD is centered usually is an incorporated place or a census designated place (CDP). Ideally, it should never subdivide such entities; when it must, as much of the place as possible should be one CCD. In some cases, the CCD is centered on a major area of significantly different land use or ownership, such as a large military base or American Indian reservation; in other situations, it can represent an area that is physiographically different from the rest of the county. A CCD should always consist of a single geographic piece that is relatively compact in shape.
The criteria for CCD boundary features are the same as those for census blocks, census tracts, and BNAs (for details, see Chapter 10, “Census Tracts and Block Numbering Areas” and Chapter 11, “Census Blocks and Block Groups”). A CCD should have easily locatable boundaries that seldom change. They should be readily discernable in the field and easy to depict on the Census Bureau’s maps. They should follow physical features, such as highways, roads, railroads, rivers, streams, power transmission lines, trails, or mountain ridges. A few kinds of non-physical features are used; for example, county lines always are CCD boundaries. In certain situations it is permissible to use point-to-point lines (comparatively short projected lines between two definite points); also permissible are conjoint city limits (a common boundary between two contiguous incorporated places). As a result of these guidelines, the CCD boundaries identify a stable set of geographic entities that allows the data user to make historical comparisons at the county subdivision level.
The CCD name usually is the same as that of the largest population center or place within it. Sometimes the name represents the two largest centers; for example, Bayard–Santa Rita. In some situations, the CCD may be named after a prominent physical feature (Castle Rock, Cripple Creek, Mount Baldy) or a distinctive region within the county (Death Valley, Everglades, Lower Keys, Tellico Plains). In many cases, a CCD name consists of the county or focal place name together with a cardinal direction indicating the portion of the county or area relative to the place covered by the CCD. If a county name (for example, Union) identifies a CCD, the directional indicator usually precedes it, as in Northwest Union. If a place name is used, the directional indicator follows it; for example, Smithville North. In all cases, the objective is to clearly identify the area of the CCD by means of an area name; CCD names always should be meaningful to data users.
Because of historical, political, legal, and economic factors, the MCDs in different States are not always comparable units in terms of their governmental powers, legal status, and administrative significance. Moreover, terms such as town, township, or district, have different meanings in different parts of the United States.
In the New England and Middle Atlantic States, the primary subdivisions of counties generally are called towns or townships. Most of these towns and townships are actively functioning units of local government and are very well known locally. Although not classified as incorporated places in the decennial census, they are legally incorporated units and have most or all the powers of incorporated places. Because of this strong functional aspect, the Census Bureau usually provides the same data tables for these MCDs as it provides for places, and also tables where MCDs and places are intermixed.
In Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont, the towns are different from the incorporated places called towns in most other States. Outside of New England, the term town usually refers to a built-up settlement or population cluster intermediate in size and governmental power between a city and a village. By contrast, the New England towns were established initially to provide government to an area rather than a specific concentration of population. Many New England towns are from 20 to 50 square miles in size, and often contain rural territory as well as one or more population concentrations. Therefore, the settlement pattern of many New England towns, except in the vicinities of the larger cities, more closely resembles that of the townships in many other States.
In New England, the towns and cities, not the county, serve as the basic units of local government. Since their establishment in the 17th century, many towns have elected their governing officials and managed their local ​affairs. The county was merely a grouping of towns, established primarily for judicial and penal purposes, and had minimal political significance. Connecticut abolished its county governments in 1960; the counties in Connecticut and Rhode Island serve only as administrative subdivisions of those States.
All incorporated places in Maine, Massachusetts, New Hampshire and Rhode Island are cities that are independent of any town. All incorporated places (cities and boroughs) in Connecticut are dependent on the town in which they are located. One borough and all but one of the State’s twenty cities are coextensive with a single town, and exercise the governmental powers of both an MCD and an incorporated place in a single elected governmental body. The incorporated places in Vermont are either cities, all of which are independent of MCDs, or villages, all of which are dependent. Unlike Connecticut, none of the dependent villages in Vermont coincide with a town.
In addition to towns in Maine, the plantations are actively functioning governmental units. There also are three Federally recognized American Indian reservations in Maine that are independent of any other MCD and that the Census Bureau treats as the statistical equivalent of MCDs. In addition, there are portions of ten Maine counties in which the Census Bureau has established UTs as the statistical equivalent of MCDs. The gores in Maine and Vermont, grants in New Hampshire and Vermont, and locations, survey townships, and purchases in New Hampshire are all nonfunctioning areal units; these kinds of entities occur in less populous areas.
The primary MCDs in New York are called towns; in New Jersey and Pennsylvania, they are called townships. These MCDs share some of the legal and geographic attributes of the New England towns in that they all are significant, active, functioning governmental units (except for one inactive township in Pennsylvania). However, there are two major differences: (1) counties in the Middle Atlantic States ​have greater governmental and administrative significance than in New England, and (2) the local inhabitants do not always perceive the MCD as constituting a single community. An illustration of the somewhat weaker community identification of MCDs in the Middle Atlantic States is the large number of separately incorporated places (nearly 2,000) and CDPs (about 800) in these three States. Although some of these separate incorporated places have the same name as their parent MCD, the majority bear the names of other communities. For example, of the approximately 1,000 incorporated places in Pennsylvania, only about 200 have a name related to their parent MCD and, in some of these situations, it is the parent MCD that was named after the place.
New York has two other types of census subcounty reporting units. All Federally and State-recognized American Indian reservations outside the boundaries of cities are separate from any town, and the Census Bureau reports data for these lands as MCD equivalents. Also, the Census Bureau treats the five boroughs that constitute New York city as MCD equivalents. Pennsylvania contains one road district—East Fork district in Potter County—that also is an actively functioning government.
The MCDs of the 12 Midwestern States evolved from the township and range system of survey townships. These survey townships, in turn, provided the geographic basis for organizing units of local government, which were called civil townships. Many civil townships consist of a single survey township. The MCDs of 11 Midwestern States use the term townships; Wisconsin uses the term town. Starting with the 1990 census, the Census Bureau also recognizes, as a separate category, charter townships in Michigan.
These MCDs, for the most part, perform less of a governmental role and are less well known locally than their counterparts in the Northeast and the Middle Atlantic States. There are exceptions—the charter townships of Michigan, the urban townships of Minnesota, and the towns of Wisconsin—all of which have the legal capacity to provide all the governmental services associated with incorporated places. In most of the other Midwestern States, the primary governmental function of township governments is the building and/or maintenance of the local roads and bridges; however, some townships, particularly in Illinois, Kansas, and Ohio, may provide fire protection, refuse disposal, libraries, cemeteries, hospitals, zoning regulation, and other types of services. In Missouri, only 23 counties have townships that are local governmental units; the 91 other counties have townships that cannot raise taxes for general-purpose government and thus are classified as nonfunctioning areal units. In Iowa, the governmental functions of the townships are so minimal that they are not recognized as general-purpose governments for the Census Bureau’s Census of Governments.
The Midwest has many incorporated places, and their relationship to MCDs varies from one State to another. In North Dakota, South Dakota, and Wisconsin, all incorporated places are independent of MCDs, as are 842 of the 854 incorporated places in Minnesota. All places are dependent on MCDs in Illinois, Indiana, and Missouri, except for Chicago, which consists of two MCD equivalents, and St. Louis, which is an independent city. In the remaining States, some places are dependent, others are independent. In Iowa, 52 of the 953 incorporated places are independent of MCDs, in Kansas 123 of 627, in Michigan 272 of 534, in Nebraska 79 of 535, and in Ohio 218 of 941.
In Illinois, Iowa, and Ohio, many of the larger incorporated places are legally coextensive with a single township. There are 19 such coextensive city-township combinations in Illinois, and in all but one case, the township has a separate government that is distinct from the one for the place. Based on an agreement between the Census Bureau and the States of Iowa and Ohio, the Census Bureau does not include the township in decennial census data tabulations when an incorporated place and a township coincide. This makes it easier to find the place in census listings and simplifies the gathering of MCD information through the BAS, since State and local governments tend not to recognize the existence of many of these nonfunctional townships. Nebraska has ten election precincts that are coextensive with a single incorporated place, and Illinois has five. Missouri has four nonfunctional townships coextensive with a single incorporated place.
In Arkansas, Louisiana, Maryland, Mississippi, North Carolina, Virginia, and West Virginia, the Census Bureau considers other types of entities as MCD county subdivisions. These MCDs are administrative or geographic entities and do not function as local governments. In these States, the only functioning governments below the county level are incorporated places; outside of the incorporated places, the county or State government provides services to the residents of these MCDs.
​The townships in Arkansas and North Carolina have no functions except that some serve as districts for the election of county officials or as areas for recording property information. The MCDs in Virginia and West Virginia, called magisterial districts, are areas for the election of representatives (supervisors in Virginia, commissioners in West Virginia) to the county government. The supervisor’s districts in Mississippi serve a similar purpose. The MCDs of Louisiana and most of Maryland are units used for conducting elections within the county. In Louisiana these are parish governing authority districts; in Maryland they are election districts, except for Anne Arundel County in which the MCDs are called assessment districts and used for taxation purposes. In all the above situations, the legal description is shortened to district in the Census Bureau’s data tabulations.
Two counties in Arkansas and two in North Carolina have territory that is not within any township. There the Census Bureau established UTs. The same situation applied to one parish in Louisiana where a portion of territory was not part of any parish governing authority district.
The Census Bureau updates its inventory of MCDs based on results of the BAS, its periodic survey of all counties, along with specified MCDs and incorporated places. In each year from 1981 through 1987, county officials (and, occasionally, State or regional officials) provided information to the Census Bureau about correct names, legal (or governmental) descriptions, and legal boundaries of MCDs. In 1988 and 1990, the BAS obtained this information directly from the officials of MCDs that had actively functioning governments. Where the MCDs were administrative subdivisions rather than functioning local governments, the BAS asked that county officials provide this information.
The BAS mailout to local governments includes maps showing the latest boundaries in the Census Bureau’s digital geographic data base, the Topologically Integrated Geographic Encoding and Referencing (TIGER) data base. The Census Bureau uses the information that the local officials provide to update its files for the decennial census; these BAS responses also are used to prepare for the population estimates program, the Census of Governments, and other surveys and programs.
The name of an MCD is its unique legal identifier; the legal (or governmental) area description, also called legal status, of an MCD is a generic category dictated by State law regarding subcounty units. It is the specific term that describes the type of MCD, such as town, township, magisterial district, and election precinct. On a nationwide basis, these terms are descriptive and not functional. (Town in one State may mean something different in another State.) In census data tables, the name of the MCD usually precedes its legal description, as in Smith township. Exceptions may occur, as in Township 6, Maguffin, where Township is the legal description of the MCD and the number 6 and Maguffin constitute portions of the name. The BAS includes a form showing the Census Bureau’s most current information on the name and legal description for ​each entity. By filling out the BAS questionnaire, the respondent provides the latest information on the legal name and description of the MCD.
The MCD boundaries used in the 1990 census were those legally in effect on January 1, 1990. The Census Bureau asks each BAS respondent if there were any boundary changes, and if so, to draw them on the maps provided. It also asks the MCD or county official to sign a statement certifying that the boundaries depicted on the map are shown correctly.
During the 1980s, some MCDs disorganized; that is, they lost their legal status as organized units of local government and reverted to the status of unorganized area. By contrast, some other areas that had been UTs in 1980 became organized units of local government. Because of these disorganizations and organizations, the Census Bureau had to update its geographic inventory. New UTs were identified, some existing UTs were combined or split, and there were boundary revisions to ensure that UT boundaries continued to follow visible features.
For the most part, the revisions made to CCDs in preparation for the 1990 census were minor. There were, however, some significant changes as a result of the establishment of census tracts and BNAs. The Census Bureau encouraged the local CSACs and the State coordinators to use the 1980 CCD boundaries as part of the new census tract or BNA framework wherever possible. In some instances, new 1990 census tracts or BNAs were delineated without regard to previously existing CCD boundaries. The Census Bureau then revised or totally redelineated CCD boundaries for the 1990 census to coincide with the new census tract/BNA boundaries.
The Census Bureau uses a system of geographic identification codes—geocodes—to identify every geographic entity for which it reports data. ​Geocodes are basic components of the TIGER data base and the geographic reference files that the Census Bureau develops and maintains to process the results of its censuses and sample surveys. Together with the TIGER data base, these files form the basis for the tabulation and dissemination of the collected data in their proper geographic entity. Geocodes obviate the need to relate data to geographic entities by name only; instead, the Census Bureau’s processing operations associate data with the geocodes that are surrogates for the names of geographic entities.
In addition to the Census Bureau’s MCD/CCD code (discussed later in this section), there are other geocodes that are part of the Federal Information Processing Standards (FIPS) system, developed by the National Institute of Standards and Technology (NIST) and now maintained by the U.S. Geological Survey. (The Census Bureau’s MCD/CCD code scheme is not part of the FIPS code scheme.) The FIPS 55 system identifies named entities in the United States, Puerto Rico, the Virgin Islands of the United States, and the Pacific Outlying Areas. The scheme features a two-digit numeric State code and a five-digit numeric locality code that uniquely identify each named entity. The system further distinguishes between types of named entities by means of a two-character class code, consisting of a leading alphabetic character and a number. There are 11 different class codes applicable to county subdivisions; in combination with the State code and locality code, they provide additional information about each county subdivision.
The FIPS 55 locality codes identify governmentally functioning MCDs within a numeric range from 00001 to 89999. The codes in this range also represent incorporated places, CDPs, and Alaska Native and American Indian areas, together with other entities not included in the tabulations of the decennial census, such as named localities, military installations, and National Parks. All these entity names are combined and listed in a single alphabetic sequence. The FIPS code range, 90000 to 98999, is reserved for CCDs and nonfunctioning MCDs where they cover whole States, whole counties, or their statistically equivalent entities. The FIPS 55 locality codes together with the FIPS 55 class codes provide a unique identifier for the ​MCDs, UTs, and CCDs within each State. The FIPS 55 class codes most commonly used to identify county subdivisions are the following:
* T1 (governmentally active MCD not coextensive with an incorporated place)
* Z1 (governmentally inactive or nonfunctioning MCD)
* Z3 (unorganized territory)
* Z5 (CCD or CSA)
For its censuses from 1960 to 1990, the Census Bureau established a series of MCD/CCD codes to identify and alphabetize all county subdivisions within each county. These are three-digit numeric identifiers, usually gapped at intervals of five (such as 005, 010, 015) that serve to organize the county subdivision names alphabetically. To identify any county subdivision, it is necessary to use not only its MCD/CCD code, but also the State code and the county code. Because the MCD code is unique only within county (for instance, the code 005 generally is repeated in every county), it is necessary to use State and county codes as well to uniquely identify MCDs/CCDs on a nationwide basis. The Census Bureau published both census and FIPS codes for all entities appearing in its 1990 data products. For the year 2000, however, the FIPS codes—State, county, locality, and Alaska Native/American Indian area—will be the only geocodes used in census data products.
The 1990 decennial census reported data for 35,298 county subdivisions, a net increase of 103 from 1980. The single most dramatic change—140 new county subdivisions in Louisiana—resulted from the replacement of the 487 police jury wards with 627 parish governing authority districts. Elsewhere, Arkansas lost 43 townships because of consolidations, West Virginia lost 33 magisterial districts as a result of redistricting, and South Dakota lost 31 townships because of disorganizations. The 57 townships in Nevada were replaced by 67 CCDs. Apart from the new CCDs in Nevada, there were few changes in the number of CCDs. Three States (Kentucky, Montana, and New Mexico) gained a single new CCD, and one CCD in Utah was consolidated with an existing CCD.
Other sizeable changes in the number of county subdivisions (29 new entities) occurred in the category of independent incorporated places. The increase resulted from new incorporations, annexations into additional counties by existing places (thus creating new MCD equivalents), and a few dependent places becoming independent. There also was a decrease of 13 plantations in Maine, most of which became towns. The disorganization of some MCDs, coupled with the identification of additional areas as being outside of nonfunctioning MCDs, resulted in a net increase of nine unorganized territories.
Figures 2-1 and 2-2 in Chapter 2 illustrate, in generalized fashion, the position of county subdivisions in the Census Bureau’s geographic hierarchy. This section discusses the geographic relationships in the 50 States; for information on Puerto Rico and the Outlying Areas, refer to Chapter 7.
County subdivisions nest within counties and statistically equivalent entities and constitute complete coverage of all their area and population. Where an incorporated place that is independent of any MCD exists in ​two counties, the Census Bureau considers each part of the place as a separate county subdivision, even though the place itself is a single governmental unit. The same situation occurs with American Indian reservations in New York State; where reservations cross county lines, the Census Bureau considers the part in each county a separate MCD.
Example 1: Geographic Areas Depicted on a Census Bureau Map
| Area | Population |
| County | 6,000 |
| MCD 1 | 0,500 |
| Place A | 4,000 |
| MCD 2 | 0,500 |
| MCD 3 | 0,500 |
| MCD 4 | 0,500 |
Example 1 illustrates the case of a county that contains an independent place. That is, the incorporated place is not governmentally subordinate to the surrounding MCDs; rather, it is independent of these MCDs. In this situation, the MCDs stop at the limits of the incorporated place, and the tabular presentation lists five pieces of geography as county subdivisions—four MCDs and one incorporated place.
The data for the MCDs exclude the data for the incorporated place they border, as shown in Example 2. Furthermore, any change in the boundaries of the incorporated place will change both the territory of, and the data for, the adjacent MCDs. The Census Bureau treats the incorporated place both as a pseudo MCD and as a place in its data tabulations.
Example 1: Geographic Areas Depicted on a Census Bureau Map
| Area | Population |
| County | 6,000 |
| MCD 1 Place A (part) | 1,500 1,000 |
| MCD 2 Place A (part) | 1,500 1,000 |
| MCD 3 Place A (part) | 1,500 1,000 |
| MCD 4 Place A (part) | 1,500 1,000 |
Example 1 illustrates the case of a county that contains a dependent place. That is, the incorporated place is governmentally subordinate to, or dependent upon, the MCDs in which it is located. In this situation, the MCD boundaries subdivide the incorporated place, the place includes territory in more than a single MCD, and the data for each MCD include the data for every incorporated place and every part of an incorporated place it contains.
The tabular presentation lists the data for the entirety of each of the four MCDs, as shown in Example 2. The MCDs include the appropriate portion of the data for the contained incorporated place as a subtotal of the MCD total. With this type of governmental structure, changes in the boundaries of the incorporated place do not change the boundaries of, or the data for, the MCDs.
| Alabama | Dependent |
| Alaska | Dependent; four cities—Anchorage, Juneau, Sitka, and Skagway—are coextensive with a single census subarea. |
| Arizona | Dependent |
| Arkansas | Dependent; one town (Tollette) is coextensive with a single township. |
| California | Dependent; one city (San Francisco) is coextensive with a single census county division (CCD) and county. |
| Colorado | Dependent; one city (Denver) is coextensive with a CCD and county. |
| Connecticut | Dependent; one borough (Naugatuck) and all but one city (Groton) are coextensive with a single town. Milford is a consolidated city containing the separate incorporated place of Woodmont borough. |
| Delaware | Dependent |
| District of Columbia | Independent; the city of Washington is treated as a single coextensive minor civil division (MCD). |
| Florida | Dependent; the consolidated city of Jacksonville is coextensive with a single CCD and county. |
| Georgia | Dependent; the consolidated city of Columbus is coextensive with a single CCD and county. |
| Hawaii | No incorporated places; by agreement with State officials, the Census Bureau recognizes areas of concentrated settlement as census designated places (CDPs) for the decennial censuses of population/housing. |
| Idaho | Dependent |
| Illinois | Dependent, except for the city of Chicago, which is independent of any township, creating two MCDs (one in each county in which Chicago is located); 19 cities—Alton, Belleville, Berwyn, Bloomington, Champaign, Cicero, East St. Louis, Evanston, Freeport, Galesburg, Granite City, Macomb, Oak Park, Peoria, Quincy, River Forest, Urbana, Warsaw, and Zion—are coextensive with a single township; 3 cities (Cairo, Golconda, and Petersburg) and 2 villages (Hecker and Valmeyer) are coextensive with a single election precinct. |
| Indiana | Dependent |
| Iowa | There are 901 dependent cities; 52 cities are independent of any township, creating 53 MCDs; most incorporated places shown as independent of any township are legally coextensive with a township that is nonfunctioning and generally not recognized by local officials; as agreed to by the State government, these townships are not identified in decennial census publications. ​ |
| Kansas | There are 504 dependent cities; 123 cities are independent of any township, creating 129 MCDs. |
| Kentucky | Dependent |
| Louisiana | Dependent except for the city of New Orleans which is independent of any MCD. |
| Maine | Independent of any MCD; 22 cities creating 22 MCDs. |
| Maryland | Dependent except Baltimore city, which is independent of any county and MCD. |
| Massachusetts | Independent of any town; 39 cities creating 39 MCDs. |
| Michigan | There are 262 dependent villages; 272 cities are independent of any township, creating 283 MCDs. |
| Minnesota | There are 12 dependent cities—Aurora, Beardsley, Calumet, Grand Rapids, Johnson, Kinney, La Prairie, Marble, Nashwauk, Ortonville, Riverton, and Taconite; 842 cities are independent of any township or unorganized territory, creating 880 MCDs. |
| Mississippi | Dependent |
| Missouri | Dependent except St. Louis city, which is independent of any county and MCD; four cities—Arnold, Edina, Kimberling City, and Lamar—are coextensive with a single township. |
| Montana | Dependent |
| Nebraska | All 392 villages and 64 cities are dependent; 79 cities are independent of any election precinct or township, creating 81 MCDs. |
| Nevada | Dependent; one incorporated place (Carson City) is coextensive with a single CCD and county. |
| New Hampshire | Independent of any MCD; 13 cities creating 13 MCDs. |
| New Jersey | Independent; there are 250 boroughs, 52 cities, 15 towns, and 3 villages creating the same numbers of MCDs. |
| New Mexico | Dependent |
| New York | There are 557 dependent villages; 61 cities are independent of any town (creating 62 MCDs) excluding New York city, which is made up of 5 MCD boroughs (one for each county within the city); 5 villages—East Rochester, Green Island, Harrison, Mount Kisco, and Scarsdale—are coextensive with a single town. |
| North Carolina | Dependent ​ |
| North Dakota | Independent of any township or unorganized territory; 366 cities creating 373 MCDs. |
| Ohio | There are 86 cities and 637 villages that are dependent; 156 cities and 62 villages are independent of any township creating 171 and 64 MCDs, respectively; 4 incorporated places have a mixed relationship (Columbus city is independent in Franklin County, but dependent in Fairfield County; Fostoria city is independent in Seneca and Wood Counties, but dependent in Hancock County; Hunting Valley village is independent in Cuyahoga County, but dependent in Geauga County; Sharonville city is independent in Hamilton County, but dependent in Butler County). Most incorporated places shown as independent of any township are legally coextensive with a township that is nonfunctioning and generally not recognized by local officials; as agreed to by the State government, these townships are not identified in decennial census publications. |
| Oklahoma | Dependent |
| Oregon | Dependent |
| Pennsylvania | Independent of any township or road district; 966 boroughs creating 977 MCDs; 55 cities creating 56 MCDs; one town creating one MCD. |
| Rhode Island | Independent of any town; eight cities creating eight MCDs. |
| South Carolina | Dependent |
| South Dakota | Independent of any township or unorganized territory; 154 cities and one town creating 162 and one MCD, respectively. |
| Tennessee | Dependent |
| Texas | Dependent |
| Utah | Dependent |
| Vermont | There are 42 dependent villages; 9 cities are independent of any gore, grant, or town, creating 9 MCDs. |
| Virginia | There are 188 dependent towns; 41 cities are independent of any county and magisterial district. |
| Washington | Dependent |
| West Virginia | Dependent; one town (Glenville) and two cities (Moundsville and Williamson) are coextensive with a single magisterial district. |
| Wisconsin | Independent; there are 188 cities and 395 villages creating 210 and 417 MCDs, respectively. |
| Wyoming | Dependent |
A place whose territory also is considered to be within the territory of one or more surrounding MCDs is called dependent. The Census Bureau considers all CDPs to be dependent places, whether the county subdivisions are MCDs or CCDs. In the 21 CCD States, the Census Bureau considers all incorporated places to be dependent; the Census Bureau also considers the incorporated places of Alaska to be dependent on the CSAs. Incorporated places in the remaining States, the 28 MCD States, can be either independent of, or dependent on, MCDs since the laws of the States vary. Table 8-4 provides detailed information on the relationships between incorporated places and county subdivisions in each State.
An incorporated place that is independent of an MCD is not considered to be part of any surrounding MCD or MCDs; the Census Bureau treats these independent incorporated places as a type of county subdivision. If an independent incorporated place exists in more than one county or statistically equivalent entity, the Census Bureau considers each county part to constitute a unique county subdivision.
Some places are geographically coextensive with an MCD; for example, independent incorporated places, and, in some situations, CDPs. In parts of the United States where MCDs are perceived as communities, such as in the Northeast, it is not uncommon for a CDP to be coextensive with an MCD of the same name.
Several geographic relationships apply throughout the 21 CCD States. The most common pattern is a CCD composed of one or more whole census tracts/BNAs; however, there are many instances where a census tract/BNA consists of two or more CCDs, or more rarely, of one CCD and part of another. In a very few cases, there is no geographic relationship between the two sets of areas.
The MCDs of the counties in the nine northeastern States are both stable geographic entities and well-known units of local government. As a result, they often figure as the geographic basis for census tracts/BNAs. An MCD generally consists of one or more census tracts/BNAs, and the boundaries of census tracts/BNAs usually do not cross the boundaries of any MCD or MCD equivalent.
By contrast, in the midwestern and southern States, the MCD boundaries usually do not coincide with groups of census tracts/BNAs, except where both sets of boundaries follow a physical feature. However, there are some instances where census tract boundaries follow nonvisible MCD lines, because the census tract criteria at one time permitted this situation.
The 1990 criteria for delineating block groups within census tracts and BNAs allowed block group boundaries to follow nonvisible MCD boundaries only in the northeastern States. When a CCD boundary was not a census tract/BNA boundary, it was preferred as a block group boundary. Where an MCD boundary, or occasionally a CCD boundary, split a physical block, the Census Bureau assigned an alphabetic suffix to identify separately each tabulation block created by the location of the county subdivision boundary.
The Federal Office of Management and Budget (OMB) establishes the standards for, and then defines, metropolitan areas (MAs) either as ​freestanding metropolitan statistical areas (MSAs) or as consolidated metropolitan statistical areas (CMSAs) and their constituent primary metropolitan statistical areas (PMSAs). In the six New England States, the geographic building blocks of MAs are MCDs or statistically equivalent entities, rather than counties as in other States. This practice harmonizes with the situation existing in New England, where the MCDs are the primary units of local government (for details, see Chapter 13, “Metropolitan Areas”).
The picture varies with regard to the geographic entities that the Census Bureau uses in its urban and rural classifications. There is no necessary geographic relationship between county subdivisions and urbanized areas (UAs) because the geographic components of UAs are places and census blocks. The same is true of non-UA urban places, which are entities that have 2,500 or more residents, because places often are subdivided by MCD/CCD boundaries.
The boundaries of other types of geographic entities sometimes conform to county subdivision boundaries. For example, MCD boundaries also may be used to bound Congressional districts. Smaller entities—voting districts, school districts, and ZIP Codes—may sometimes constitute an MCD or portions of their boundaries may coincide with MCD or CCD boundaries.
* ↑ At the time of the 1990 census, there were UTs in Kansas, but not in Indiana.
* ↑ U.S. Bureau of the Census, Census County Divisions, Past and Future, [by Dr. Robert C. Klove] Technical Paper No. 30, Washington, DC, 1973.
* ↑ The Alaska Native Claims Settlement Act (P.L. 92-203) established 13 business and nonprofit corporate entities to carry out the business and nonprofit operations established by and for Native Alaskans under the Act. Twelve have specific boundaries and cover the entire State of Alaska except for the Annette Islands Reserve; the thirteenth covers Alaska Natives not resident in Alaska who do not identify with any of the other 12 corporations. For further information, refer to Chapter 5, “American Indian and Alaska Native Areas.”
​Notes and References