# Baltimore County, Maryland

Baltimore County (/ˈbɔːltɪmɔːr/ BAWL-tim-or, locally: /bɔːldəˈmɔːr/ bawl-da-MOR or /ˈbɔːlmər/ BAWL-mər) is the third-most populous county in the U.S. state of Maryland. The county is part of the Central Maryland region of the state. Baltimore County partly surrounds but does not include the independent city of Baltimore. It is part of the Northeast megalopolis, which stretches from Northern Virginia in the south to Boston in the north and includes major American population centers, including New York City and Philadelphia. Major economic sectors in the county include education, government, and health care. As of the 2020 census, the population was 854,535. The county is home to several universities, including Goucher College, Stevenson University, Towson University, and University of Maryland, Baltimore County.

## History
### 17th century

The name "Baltimore" derives from Cecil Calvert, 2nd Baron Baltimore (1605–1675), proprietor of the colonial-era Province of Maryland, and the town of Baltimore in County Cork, Ireland. The earliest known documentary record of the county is dated January 12, 1659, when a writ was issued on behalf of the General Assembly of Maryland to its sheriff.
The county was founded in 1659, and is now one of 23 counties in the state. The initial Baltimore County was larger geographically than it is currently, including most of northeastern Maryland, which was then the northwestern frontier of the Province and included the present-day jurisdictions of Baltimore City, Cecil and Harford Counties, and parts of Carroll, Anne Arundel, Frederick, Howard, and Kent Counties.
In 1674, a proclamation of the Proprietor established the then-extensive boundary lines for old Baltimore County. Over the next century, various segments of the old county were sliced off as population and settlements increased in fringe regions. A portion of northeastern Baltimore County, as well as a portion of northwestern Kent County, was split off to create Cecil County. In 1748, a portion of western Baltimore County, as well as a portion of Prince George's County to the south, were split off to create Frederick County. In 1773, Harford County to the east was split off, and in 1837 another part of western Baltimore County was combined with a part of eastern Frederick County to create Carroll County. After the adjustment of Baltimore County's southern boundary with Anne Arundel County, stated to be the upper Middle and Western Branches of the Patapsco River in 1727, a portion of the county's northwestern area was designated in 1838 as the "Western District" or "Howard District" of Arundel and in 1851 was officially separated to form Howard County.
Prior to 1674, Baltimore County court sessions were held in private residences, according to sketchy documentary evidence. In 1674, the General Assembly passed "An Act for erecting a Court-house and Prison in each County within this Province". The site of the courthouse, jail and county seat for Baltimore County was evidently "Old Baltimore" near the Bush River on land that in 1773 became part of Harford County.
The exact location of Old Baltimore is Chilbury Point on the north side of the Bush River owned by the Garrison of the present-day Aberdeen Proving Ground (APG), a U.S. Army weapons testing facility. It is a popular spot of local boaters. APG's Cultural Resource Management Program attempted to find Old Baltimore, contracting with R. Christopher Goodwin & Associates (Goodwin). Goodwin first performed historical and archival work and coordinated with existing landscape features to locate the site of Old Baltimore. APG's Explosive Ordnance Disposal of Army personnel defused any unexploded ordnance. In 1997–1998. Goodwin dug 420 test pits, uncovering artifacts including a King Charles II farthing coin, and French and English gun flints. An unearthed brick foundation proved to be the remains of the tavern owned by colonist James Phillips. Another prominent landholder in Old Baltimore was William Osbourne, who operated the ferry across the Bush River.
In 1683, the Maryland General Assembly passed "An Act for Advancement of Trade" to "establish towns, ports, and places of trade, within the province." One of the towns established by the act was "on Bush River, on Town Land, near the Court-House". The courthouse on the Bush River referenced in the 1683 Act was in all likelihood the one created by the 1674 Act. "Old Baltimore" was in existence as early as 1674, but no documents describe what may have preceded it.
By 1695, the "Old Baltimore" courthouse had evidently been abandoned. County justices put the site up for sale. Apparently a new courthouse at "Simm's Choice" on the Baltimore County side of Little Gunpowder Falls had been under construction since 1692.

### 18th century

In 1700, builder Michael Judd sold it to the county justices. This change of location, away from the Bush River area, reflects the growing economic and political importance of the Gunpowder region. During the next decade, the county seat moved to Joppa.
By 1724, the legislative assembly authorized Thomas Tolley, Capt. John Taylor, Daniel Scott, Lancelot Todd, and John Stokes to purchase 20 acres from "Taylor's Choice," a tract named after John Taylor. The assembly's ordinance directed that the land be divided into 40 lots with streets and alleys to accompany the courthouse and jail erected previously. By 1750, about 50 houses (including a few large two-story brick structures), a church (St. John's Anglican Parish), a courthouse, three stone warehouses, inns, taverns, stores, a public wharf and a "gallows-tree" with an "Amen Corner" with pillories and whipping posts (now located northeast of the City of Baltimore near present-day suburban "Joppatowne" off Harford Road) existed.
A new port and wharfing site, Elkridge Landing, on the upper Patapsco River's Western Branch, became prosperous in the 18th century. It was established on the "falls" of the river, below the rapids and rocks, where the river was deep enough for loaded sailing merchantmen. The landing was a designated "port of entry" and was the terminus of several "rolling roads" on which horse or oxen-drawn hogsheads (huge barrels) packed with tobacco were wheeled down to the Landing/port to be loaded on ships sailing for London and Europe. Gradually the site silted-up from soil erosion and poor farming cultivation on the upper Patapsco, and the maritime economy of the Landing faded. In the 19th century, it became an important stop on the Baltimore and Ohio Railroad and the main north-south East Coast highway for wagons and carriages. Still, later it was on Washington Boulevard (designated U.S. Route 1) by 1926.
With a bit of financial pressure, and after paying for the cost of a new courthouse (300 pounds sterling), dominant business, commercial and political residents of the Town of Baltimore were able to have the Maryland General Assembly relocate the county seat to their growing port town. In 1768, following receipt of petitions for and against the relocation, the General Assembly passed an Act that moved the county seat from Joppa to Baltimore. The first courthouse was constructed in 1768 at a new Courthouse Square at present-day North Calvert Street, between East Lexington and East Fayette Streets.

### 19th century

The city of Baltimore, Jonestown, and Fells Point were incorporated as the City of Baltimore in 1796–1797. The city remained a part of surrounding Baltimore County and continued to serve as its county seat from 1768 to 1851.
The site of the courthouse is now "Battle Monument Square", constructed 1815–1822 to commemorate the city and county defense in the War of 1812, including the bombardment of Fort McHenry by the British Royal Navy fleet in the Patapsco River, the two-day stand-off in fortifications dug east of the city on Loudenschlager's Hill (now "Hampstead Hill" in today's Patterson Park) and the earlier Battle of North Point in "Godly Woods" on the "Patapsco Neck" peninsula in the southeastern portion of the county, during September 12–14, 1814. These events have been commemorated ever since by Defenders Day, an annual city, county, and state official holiday on September 12.
A second city-county courthouse constructed in 1805–1809 was moved to the western side of the Square at North Calvert and East Lexington. A third courthouse including the lower magistrates, commissioners, district and circuit courts, orphans (inheritances/wills) court, small claims court and the old Supreme Bench of Baltimore City was constructed on the entire western block of North Calvert, East Lexington, East Fayette and Saint Paul Streets from 1896 to 1900.
In 1816, the City of Baltimore annexed from Baltimore County several parcels of land known as the "Precincts" on its west, north, east and southwest sides. The County separated from the city (which it surrounds on the east, north, and west) on July 4, 1851, as a result of the adoption of the 1851 second state constitution. Baltimore became one of the few "independent cities" in the United States, putting it on the same level with the state's other 23 counties and granting limited "home rule" powers outside the authority of the Maryland General Assembly.
Towsontown was voted in a referendum by the voting citizens as the new "county seat" on February 13, 1854. The City of Baltimore continued annexing land from the county, extending its western and northern boundaries in 1888. The factory and business owners in the eastern industrial communities of Canton and Highlandtown resisted and opposed annexation, but were annexed 30 years later. The last major annexation took place in 1918–1919, which again took territory from the county on all three sides (west, north, and east) and to the south for the first time from Anne Arundel County, along the south shores of the Patapsco River.

### 20th century

A new Baltimore County Courthouse was authorized to be built facing Washington Avenue, between Chesapeake and Pennsylvania Avenues to replace the previous courthouse and governmental offices then centered for near 85 years in the city, which had been the official "county seat" since just before the American Revolution. Later surrounded by manicured flower gardens, shrubs and curved walkways, the historical landmark is built of local limestone and marble. It was completed and dedicated in 1855. Wings and annexes were added in 1910, 1923 and 1958. By the 1970s, the county's legal system and governmental offices had grown so much that a separate modernistic "County Courts Building" was erected to the west behind the old Courthouse with its annexes, separated by a paved plaza which is used for employee/visitors relaxations and official ceremonies.
A constitutional amendment to the 1867 Maryland Constitution was approved by referendum in 1948, prohibiting any future annexations without approval from residents in affected territories.
Extensive city-county hostilities came during the Civil Rights Movement, and by the 1980s the county's older inner suburbs faced increasing urban social ills. An atmosphere of cooperation emerged with the drawing of cross-border state assembly districts, organizing of regional government agencies, and increasing state assumption of powers.
The county has a number of properties and sites of local, state and national historical interest on the National Register of Historic Places which is maintained by the National Park Service of the U.S. Department of the Interior by the "Historic Sites Act" of August 1935.
In 1985, the Clarence M. Mitchell Jr. City Circuit Courthouse was named in honor of Baltimorean and Civil Rights Movement leader Clarence M. Mitchell Jr..

## Politics and government

Baltimore County has had a charter government since 1956. The government consists of a County Executive and a seven-member County Council. The County Executive and Council members are elected in years of gubernatorial elections. The County Executive may serve a maximum of two consecutive terms.
Without incorporated cities or towns, the county government provides all local services to its residents, many of which are normally associated with city-type governmental agencies.
In 1956, the County adopted an "executive-council" system of government with "at large" representatives, replacing its traditional system of an elected Board of County Commissioners. Since then it has had eleven county executives and one "acting" executive, of which ten were Democrats and two were Republicans. The former Vice President of the United States, Spiro T. Agnew, served as the third executive from 1962 to 1966 and subsequently was elected Governor of Maryland, serving from 1967 to 1969. He was later accused of corruption and bribery while serving as County executive and continuing to accept bribes as the state's governor and as U.S. vice president. He pleaded "no contest" to unprecedented Federal criminal charges. He was forced to resign the Vice Presidency in 1973.
Politically, Baltimore County leans Democratic, but not as overwhelmingly as Baltimore City. In general, the northern portions of the county lean Republican, while the southern portion is more Democratic.

### State's attorney

The Baltimore County State's Attorney is responsible for prosecuting the felony, misdemeanor, and juvenile cases that occur in the county. As of 2017, the State's Attorney was Scott Shellenberger (Democrat). He followed Sandra A. O'Connor, a Republican who served eight terms before retiring in 2006.

### Law enforcement

The Baltimore County Police Department is responsible for police services.
Established in the mid-17th century, the Sheriff of Baltimore County was at first filled by county justices from 1662 to 1676. After 1676, the Court submitted three names from which the colonial governor chose a sheriff. Although terms of office initially varied, by 1692, a uniform two-year term was imposed. In 1699 a three-year term with separate commissions was adopted. The sheriff acted as the chief local representative of the proprietary government. His duties included the collection of all public taxes and after 1692, the collection of the yearly poll tax of forty pounds of tobacco for the support of the Anglican (Church of England) clergy and parishes. A sheriff received a percentage of collected monies, generally about five percent. He also received a yearly salary for duties such as reporting to the governor on affairs within the county, taking/estimating the census periodically, conveying official laws and proprietary requests to the county courts and selecting juries for court sessions. Along with enforcing all provincial laws, he posted new laws in public places. While his primary duty was to serve the Proprietor, the sheriff was aware of problems faced by poor planters and tradesmen. With taxes, yearly quit-rents and other costly expenditures, many of the poorer settlers were unable to pay their obligations when due. The sheriff often extended credit to these planters and paid their immediate obligations out of his own pocket. This lessened the impact of taxes for the poor, who repaid the sheriff after their harvests were brought in.
The modern Baltimore County Sheriff's Department is responsible for security of the two major County Circuit Courts buildings and various courtrooms elsewhere as well as process and warrant service. Sheriff's Deputies are sworn police officers and share the same powers of the more recently organized County Police Department. As of 2019, the Baltimore County Sheriff is a Democrat, R. J. Fisher.
The Maryland State Police is headquartered at 1201 Reisterstown Road in the Pikesville CDP.
The Federal Bureau of Investigation (FBI) Baltimore field office is located in Milford Mill.

### Fire Department

The Baltimore County Fire Department (B.Co.F.D.) provides fire protection, emergency medical services and emergency rescue services to the county and surrounding areas, including Baltimore City, through mutual-aid pacts with those jurisdictions. The department consists of both paid and volunteer companies that provide services to overlapping territories. Twenty-five career (paid) stations and 28 volunteer stations operate there. More than 1,000 paid personnel and more than 2,000 volunteers serve in the department. The department conducts annual fire inspections on commercial properties, fire investigation and fire prevention education activities as well as water and tactical rescue.
Sworn in as fire chief on July 1, 2019, Joanne R. Rund is the first female chief to be permanently appointed to the position.

### County executives

The Baltimore County Executive oversees the executive branch of the County government, which is charged with implementing County law and overseeing the government operations.
List of County Executives
* 1956–1958, Michael J. Birmingham (D)
* 1958–1962, Christian H. Kahl (D)
* 1962–1966, Spiro T. Agnew (R)
* 1966–1974, Dale Anderson (D)
* 1974–1974, Frederick L. Dewberry (D) (acting)
* 1974–1978, Theodore G. Venetoulis (D)
* 1978–1986, Donald P. Hutchinson (D)
* 1986–1990, Dennis F. Rasmussen (D)
* 1990–1994, Roger B. Hayden (R)
* 1994–2002, C. A. Dutch Ruppersberger III (D)
* 2002–2010, James T. Smith Jr. (D)
* 2010–2018, Kevin B. Kamenetz (D)
* 2018–2018, Donald I. Mohler III (D)
* 2018–2025, John A. Olszewski Jr. (D)
* 2025–2025, D'Andrea Walker (acting)
* 2025–present, Katherine A. Klausmeier (D)
Notes: Anderson resigned after being convicted of several crimes and sentenced to prison. Kamenetz died on May 10, 2018. County Administrative Officer Frederick J. Homan was acting county executive until the county council named Mohler to serve the remainder of Kamenetz's term.

### County council

The County Council adopts ordinances and resolutions and holds the county's legislative powers.
As of April 2023, the council has 4 Democrats and 3 Republicans.
Baltimore County Council Membership :
| District | Name | Party |
| District 1 | Pat Young | Democratic |
| District 2 | Izzy Patoka | Democratic |
| District 3 | Wade Kach | Republican |
| District 4 | Julian E. Jones Jr. | Democratic |
| District 5 | David S. Marks | Republican |
| District 6 | Mike Ertel | Democratic |
| District 7 | Todd K. Crandell | Republican |

#### Baltimore County Council Historical Membership

| Name | Years Served | District | Party |
| Vicki Almond | 2010–2018 | 2 | D |
| Joseph Bartenfelder | 1994–2010 | 6 | D |
| Cathy Bevins | 2010–2022 | 6 | D |
| Vincent Gardina | 1990–2010 | 5 | D |
| Todd Huff | 2010–2014 | 2 | R |
| Kevin B. Kamenetz | 1994–2010 | 2 | D |
| S. G. Samuel Moxley | 1994–2010 | 1 | D |
| Kenneth Oliver | 2002–2014 | 4 | D |
| John A. Olszewski Sr. | 1998–2014 | 7 | D |
| Thomas E. Quirk | 2010–2022 | 1 | D |
| T. Bryan McIntire | 1994–2010 | 2 | R |
| Louis L. DePazzo | 1996–1998 | 7 | D |
| Douglas B. Riley | | 4 | R |
| Berchie Lee Manley | | 1 | R |
| Melvin G. Mintz | | 2 | D |
| C. A. (Dutch) Ruppersberger III | | 3 | D |
| William A. Howard IV | | 6 | R |
| Donald C. Mason | 1990–1994 | 7 | D |

### Politics

Baltimore County is somewhat of a bellwether for Maryland politics. While it leans slightly Republican compared to the state as a whole, Republicans running for statewide office must carry it solidly to win a statewide election.
After going Republican in all but one presidential election from 1944 to 1988, it has voted for the Democratic candidate for president in each election since 1992. Along with neighboring Howard County, it has voted for the state-wide presidential winner in 10 straight elections, the longest such streak in the state. However, in gubernatorial elections, it has often gone Republican (1994, 1998, 2006) even as a Democratic candidate was elected governor. In the 2014 gubernatorial election Republican Larry Hogan won Baltimore County by over 20 points (59.03% to 38.89%).
Voter registration and party enrollment as of March 2024 :
| | Democratic | 306,276 | 53.59% |
| | Republican | 137,055 | 23.98% |
| | Unaffiliated | 117,601 | 20.58% |
| | Libertarian | 2,661 | 0.47% |
| | Other parties | 7,879 | 1.38% |
| Total | Total | 571,472 | 100% |
United States presidential election results for Baltimore County, Maryland :
| Year | Republican / Whig | Republican / Whig | Democratic | Democratic | Third party(ies) | Third party(ies) |
| Year | No. | % | No. | % | No. | % |
| 2024 | 149,560 | 36.22% | 249,958 | 60.53% | 13,397 | 3.24% |
| 2020 | 146,202 | 35.24% | 258,409 | 62.28% | 10,321 | 2.49% |
| 2016 | 149,477 | 38.26% | 218,412 | 55.91% | 22,793 | 5.83% |
| 2012 | 154,908 | 40.26% | 220,322 | 57.26% | 9,552 | 2.48% |
| 2008 | 158,714 | 41.66% | 214,151 | 56.22% | 8,073 | 2.12% |
| 2004 | 166,051 | 46.98% | 182,474 | 51.62% | 4,954 | 1.40% |
| 2000 | 133,033 | 43.75% | 160,635 | 52.83% | 10,416 | 3.43% |
| 1996 | 114,449 | 42.39% | 132,599 | 49.12% | 22,920 | 8.49% |
| 1992 | 126,728 | 39.21% | 143,498 | 44.40% | 52,994 | 16.40% |
| 1988 | 163,881 | 57.04% | 121,570 | 42.32% | 1,844 | 0.64% |
| 1984 | 171,929 | 61.31% | 106,908 | 38.12% | 1,591 | 0.57% |
| 1980 | 132,490 | 47.33% | 121,280 | 43.33% | 26,147 | 9.34% |
| 1976 | 143,293 | 54.73% | 118,505 | 45.27% | 0 | 0.00% |
| 1972 | 175,897 | 70.30% | 70,309 | 28.10% | 4,018 | 1.61% |
| 1968 | 108,930 | 49.74% | 80,798 | 36.89% | 29,283 | 13.37% |
| 1964 | 77,870 | 39.92% | 117,153 | 60.06% | 50 | 0.03% |
| 1960 | 96,027 | 50.43% | 94,396 | 49.57% | 0 | 0.00% |
| 1956 | 104,021 | 68.30% | 48,270 | 31.70% | 0 | 0.00% |
| 1952 | 81,898 | 62.59% | 48,476 | 37.04% | 484 | 0.37% |
| 1948 | 41,846 | 56.18% | 31,883 | 42.80% | 761 | 1.02% |
| 1944 | 34,047 | 56.44% | 26,275 | 43.56% | 0 | 0.00% |
| 1940 | 26,652 | 46.60% | 30,360 | 53.08% | 186 | 0.33% |
| 1936 | 18,893 | 39.71% | 28,367 | 59.62% | 316 | 0.66% |
| 1932 | 13,938 | 35.29% | 24,626 | 62.35% | 930 | 2.35% |
| 1928 | 23,889 | 60.17% | 15,632 | 39.37% | 180 | 0.45% |
| 1924 | 9,383 | 43.32% | 9,424 | 43.51% | 2,854 | 13.18% |
| 1920 | 12,432 | 56.04% | 9,365 | 42.22% | 386 | 1.74% |
| 1916 | 12,633 | 44.47% | 15,226 | 53.60% | 547 | 1.93% |
| 1912 | 4,247 | 19.03% | 11,524 | 51.65% | 6,541 | 29.32% |
| 1908 | 10,197 | 48.60% | 10,297 | 49.08% | 488 | 2.33% |
| 1904 | 7,570 | 43.89% | 9,394 | 54.47% | 282 | 1.64% |
| 1900 | 9,348 | 49.23% | 9,147 | 48.18% | 492 | 2.59% |
| 1896 | 9,211 | 53.59% | 7,110 | 41.37% | 867 | 5.04% |
| 1892 | 5,165 | 40.10% | 7,225 | 56.09% | 490 | 3.80% |
| 1888 | 5,224 | 43.06% | 6,464 | 53.28% | 443 | 3.65% |
| 1884 | 6,257 | 43.63% | 7,856 | 54.78% | 227 | 1.58% |
| 1880 | 5,351 | 42.16% | 7,321 | 57.68% | 21 | 0.17% |
| 1876 | 5,001 | 40.64% | 7,304 | 59.36% | 0 | 0.00% |
| 1872 | 3,774 | 47.49% | 4,173 | 52.51% | 0 | 0.00% |
| 1868 | 2,335 | 34.79% | 4,377 | 65.21% | 0 | 0.00% |
| 1864 | 2,402 | 50.11% | 2,391 | 49.89% | 0 | 0.00% |
| 1860 | 37 | 0.52% | 449 | 6.25% | 6,693 | 93.23% |
| 1856 | 8 | 0.12% | 3,155 | 47.32% | 3,504 | 52.56% |
| 1852 | 2,527 | 48.57% | 2,669 | 51.30% | 7 | 0.13% |
| 1848 | 13,001 | 48.61% | 13,664 | 51.09% | 79 | 0.30% |
| 1844 | 10,714 | 48.01% | 11,602 | 51.99% | 0 | 0.00% |
| 1840 | 9,237 | 48.15% | 9,946 | 51.85% | 0 | 0.00% |
| 1836 | 6,699 | 44.90% | 8,222 | 55.10% | 0 | 0.00% |
| 1832 | 4,248 | 34.88% | 7,930 | 65.12% | 0 | 0.00% |
| 1828 | 5,917 | 43.37% | 7,725 | 56.63% | 0 | 0.00% |
| 1824 | 3,980 | 40.53% | 0 | 0.00% | 5,840 | 59.47% |

### Federal government

Baltimore County is represented by Republican Andy Harris of Maryland's 1st congressional district, Democrat Johnny Olszewski of the 2nd district, and Democrat Kweisi Mfume of the 7th district.

## Geography

According to the U.S. census bureau, the county covers 682 square miles (1,770 km$^2$), 598 square miles (1,550 km$^2$) of which is land and 83 square miles (210 km$^2$) (12%) of which is water. It is the third-largest county in Maryland by land area. The larger portion of the terrain consists of hills often rising to a height of 800 feet (240 m) above tide water.
The highest elevation is approximately 960 feet (290 m) above sea level at Maryland's state border with Pennsylvania near Steltz. The lowest elevation is sea level along the shoreline of Chesapeake Bay.
Much of the county is suburban, straddling the border between the Piedmont plateau to the northwest and in the southern and southeastern regions of the county bordering the Patapsco River and the Chesapeake Bay, the Atlantic coastal plain. Northern Baltimore County is primarily rural, with a landscape of rolling hills and deciduous forests characteristic of the Southeastern mixed forests and shares the geography with its neighbors to the east and west, Carroll County and Harford County, and going north across the historic Mason–Dixon line into Adams County and York County in south central Pennsylvania.

### Climate

The county has a humid subtropical climate (Cfa) except in the northern tier where a hot-summer humid continental climate (Dfa) exists. Average monthly temperatures in Towson range from 33.3 °F in January to 76.9 °F in July. The county has three hardiness zones: 6b in some higher northern areas, 7a in most of the county by area, and 7b in areas close enough to the Chesapeake Bay or the City of Baltimore.

### Adjacent counties and independent city

* York County, Pennsylvania (north)
* Carroll County (west)
* Harford County (east)
* Anne Arundel County (south)
* Kent County (Southeast)
* Howard County (southwest)
* Baltimore City (south)

### National protected area

* Hampton National Historic Site

### State protected area

* Soldiers Delight Natural Environment Area

## Transportation
### Major roads and highways

* I-70
* I-83
* I-95
* I-195
* I-695
* I-795
* I-895
* US 1
* US 1 Alt.
* US 40
* MD 7
* MD 25
* MD 26
* MD 30
* MD 41
* MD 43
* MD 45
* MD 88
* MD 91
* MD 122
* MD 125
* MD 129
* MD 130
* MD 131
* MD 133
* MD 134
* MD 137
* MD 138
* MD 139
* MD 140
* MD 144
* MD 145
* MD 146
* MD 147
* MD 150
* MD 151
* MD 165
* MD 166
* MD 295
* MD 372
* MD 439
* MD 542
* MD 562
* MD 648
* MD 695
* MD 700
* MD 702
* MD 940

### Transit

The Maryland Transit Administration (MTA) operates three rail systems—one light rail, one rapid transit, and one commuter rail—in the Baltimore area; all three systems have stations in Baltimore County. The heavy-rail Metro SubwayLink runs northwest of the city to Owings Mills; the Light RailLink system runs north of Baltimore City to Hunt Valley and south of the city through Baltimore Highlands with some routes terminating at Baltimore/Washington International Thurgood Marshall Airport, Maryland. Commuter MARC Train service is available in the county at Halethorpe, St. Denis, and Martin State Airport stations.
The MTA's local and regional bus services also serve Baltimore County.

### Rail

Both CSX Transportation and Amtrak mainlines run through the county. Former rail lines running through the County beginning in the 19th Century were the Maryland and Pennsylvania Railroad (MPR) and the Northern Central Railway (previously the Baltimore and Susquehanna Railroad, later becoming part of the old Pennsylvania Railroad). MPR and parts of the Northern Central were abandoned. The present-day streetcar/trolley line coming north from Anne Arundel County and the International Airport through Baltimore City uses the Northern Central right-of-way south of Cockeysville and Timonium; starting slightly north of that, the right-of-way was converted into the popular hiking, biking and jogging pathway from Loch Raven to the Mason–Dixon line with Pennsylvania known now as the Torrey C. Brown Rail Trail, named for a former state secretary of natural resources.

## Demographics
### 2020 census

Baltimore County, Maryland – Racial and ethnic composition Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos may be of any race. :
| Race / Ethnicity (NH = Non-Hispanic) | Pop 2010 | Pop 2020 | % 2010 | % 2020 |
| White alone (NH) | 504,556 | 443,263 | 62.68% | 51.87% |
| Black or African American alone (NH) | 206,913 | 252,724 | 25.70% | 29.57% |
| Native American or Alaska Native alone (NH) | 2,107 | 1,942 | 0.26% | 0.23% |
| Asian alone (NH) | 39,865 | 54,701 | 4.95% | 6.40% |
| Pacific Islander alone (NH) | 255 | 252 | 0.03% | 0.03% |
| Some Other Race alone (NH) | 1,445 | 4,461 | 0.18% | 0.52% |
| Mixed Race or Multi-Racial (NH) | 16,153 | 35,700 | 2.01% | 4.18% |
| Hispanic or Latino (any race) | 33,735 | 61,492 | 4.19% | 7.20% |
| Total | 805,029 | 854,535 | 100.00% | 100.00% |

### 2010 census

As of the 2010 United States Census, 805,029 people, 316,715 households, and 205,113 families resided there. The population density was 1,345.5 inhabitants per square mile (519.5/km$^2$). The 335,622 housing units supported an average density of 561.0 per square mile (216.6/km$^2$). The racial makeup of the county was 64.6% white, 26.1% black or African American, 5.0% Asian, 0.3% American Indian, 1.6% from other races, and 2.4% from two or more races. Those of Hispanic or Latino origin made up 4.2% of the population. In terms of ancestry, 20.7% were German, 14.6% were Irish, 8.7% were English, 7.4% were Italian, 5.8% were Polish and 5.0% were American.
Of the 316,715 households, 31.4% had children under the age of 18 living with them, 45.5% were married couples living together, 14.5% had a female householder with no husband present, 35.2% were non-families, and 28.3% of all households were made up of individuals. The average household size was 2.48 and the average family size was 3.04. The median age was 39.1 years.
The household median income was $63,959 and the median income for a family was $78,385. Males had a median income of $53,104 versus $43,316 for females. The per capita income for the county was $33,719. About 5.3% of families and 8.1% of the population were below the poverty line, including 10.1% of those under age 18 and 7.6% of those age 65 or over.

## Economy

Among the county's major employers are MedStar Franklin Square Medical Center on the east side in Rossville, the Social Security Administration, the national headquarters of which are in Woodlawn, and The Black & Decker Corporation, in Towson. As of 2009, the county's workforce totaled 410,100, with 25% employed in the fields of education, health and human services, 10% in retailing, and less than 1% in agriculture.

### Top employers

According to the county's 2011 Comprehensive Annual Financial Report, the top employers in the county are concentrated in the government, medical and educational fields. The only commercial entity is Erickson Living:
| # | Employer | # of Employees |
| 1 | Social Security Administration/CMS | 14,948 |
| 2 | Baltimore County Public Schools | 14,608 |
| 3 | Baltimore County | 8,429 |
| 4 | MedStar Franklin Square Medical Center | 3,500 |
| 5 | Towson University | 3,344 |
| 6 | Greater Baltimore Medical Center | 3,331 |
| 7 | St. Joseph Medical Center | 3,330 |
| 8 | University of Maryland, Baltimore County | 3,258 |
| 9 | Erickson Living | 3,070 |
| 10 | The Sheppard and Enoch Pratt Hospital | 2,380 |

### Agriculture

The University of Maryland Extension system provides Extension for the county. The state Farm Bureau oversees the County Farm Bureau here.
Switchgrass (Panicum virgatum) is a potential energy crop and soil improver however it does not compete well with some warm-season annual grass weeds and broadleaf weeds here. Sadeghpour et al., 2014 finds that various winter cereals including oat and rye are helpful covers for weed control, rye moreso than oat. However they still found that herbicide (specifically atrazine or quinclorac) is needed as supplemental weed control. Osipitan et al., 2018 believe this result generalizes to early season cover cropping for weed control in general.

## Education
### Colleges and universities

The University System of Maryland maintains two universities in Baltimore County:
* Towson University in Towson, (founded 1866 as Maryland State Normal School in Baltimore City; renamed Maryland State Teachers College at Towson, 1935; Towson State College, 1963; Towson State University, 1976, Towson University, 1997).
* University of Maryland, Baltimore County in Catonsville, founded 1966.
The two private colleges in Baltimore County are:
* Goucher College (in Towson), founded as Women's College of Baltimore, 1885.
* Stevenson University, formerly Villa Julie College (campuses in Stevenson and Owings Mills).
Other schools with a campus in Baltimore County:
* Loyola College in Maryland (in Hunt Valley, main campus in Baltimore at North Charles Street and East Cold Spring Lane, [formerly Loyola College, founded 1852]).
* The Community College of Baltimore County (CCBC), with campuses in Catonsville, Essex, and Dundalk.

### Public schools

All public schools in Baltimore County are operated by Baltimore County Public Schools, the sole school district in the county, with the exception of the Imagine Me Charter School, which opened August 2008.

### Private schools

Baltimore County has a number of private schools at the K-12 grade levels. Among them are:
* Arlington Baptist High School
* Baltimore Actors Theatre Conservatory
* Beth Tfiloh Dahan Community School
* The Boys' Latin School of Maryland
* Calvert Hall College High School
* Cambridge School of Baltimore
* Concordia Preparatory School
* Garrison Forest School
* Immaculate Conception School
* Jemicy School
* Loyola Blakefield
* Maryvale Preparatory School
* McDonogh School
* Mount de Sales Academy
* Notre Dame Preparatory School
* Oldfields School (all-girls')
* Our Lady of Grace School
* Our Lady of Mt. Carmel
* The Park School
* St. James Academy in Monkton
* St. Paul's School & St. Paul's School for Girls
* St. Timothy's School (all-girls')

## Communities
### Census-designated places

All areas in Baltimore County are unincorporated and have no legal jurisdiction over their area.
The following census-designated places recognized by the U.S. Census Bureau:
* Arbutus
* Baltimore Highlands
* Bowleys Quarters
* Carney
* Catonsville
* Cockeysville
* Dundalk
* Edgemere
* Essex
* Garrison
* Hampton
* Kingsville
* Lansdowne
* Lochearn
* Lutherville
* Mays Chapel
* Middle River
* Milford Mill
* Overlea
* Owings Mills
* Parkville
* Perry Hall
* Pikesville
* Randallstown
* Reisterstown
* Rosedale
* Rossville
* Timonium
* Towson (county seat)
* White Marsh
* Woodlawn

### Unincorporated communities

Although not formally Census-Designated Places, these other communities are known locally and, in many cases, have their own post offices and are shown on roadmaps:
* Baldwin
* Boring
* Bradshaw
* Brooklandville
* Butler
* Chase
* Fork
* Fort Howard
* Germantown
* Glen Arm
* Glencoe
* Glyndon
* Halethorpe
* Hereford
* Hunt Valley
* Hydes
* Jacksonville
* Long Green
* Maryland Line
* Monkton
* Nottingham
* Oella
* Parkton
* Phoenix
* Ruxton
* Sparks
* Sparrows Point
* Stevenson
* Trump
* Turners Station
* Upper Falls
* Upperco
* White Hall

## Notable people

* Spiro Agnew, former Vice President of the United States, Baltimore County Executive, and governor of Maryland
* Holmes Alexander (1906–1985), historian, journalist, columnist, and member of the Maryland House of Delegates
* All Time Low, punk-rock band, formed in 2003
* Peter Angelos, prominent attorney and owner, Baltimore Orioles
* Brian Balmages, composer
* Mario Dewar Barrett, famous R&B singer
* Mark Belanger, former Oriole shortstop
* Ryan Boyle, professional lacrosse player
* A. J. Burnett, MLB pitcher
* David Byrne, lead singer Talking Heads
* Tom Clancy, well-known author of political thrillers
* Kevin Clash, puppeteer most famous for Sesame Street's Elmo
* Louis S. Diggs, Baltimore County historian
* Samuel Durrance, astronaut/physicist
* Robert Ehrlich, 60th Governor of Maryland
* Jane Frank (1918–1986) artist (born in Baltimore, lived in Owings Mills and Towson most of her adult life)
* Cinder Road. Band named after a road in Lutherville
* Lee Gatch, artist (born in a small rural community near Baltimore)
* Jim Gentile, former Oriole and Dodger first baseman
* Conor Gill, professional lacrosse player
* Ira Glass, host and producer of This American Life
* Elaine Hamilton-O'Neal, abstract expressionist artist and Fulbright scholar
* William H. Harrison (USMC), brigadier general in the Marine Corps during World War II
* Emily Spencer Hayden, photographer
* Billy Hunter, former major league baseball shortstop and manager
* Foxhall P. Keene, horse breeder and Olympic gold medalist polo player
* Stacy Keibler, actress and model
* Harvey Ladew, designer of Ladew Topiary Gardens
* Bucky Lasek, famous vert ramp skateboarder, from Dundalk
* Hae Min Lee, Murder victim
* G. E. Lowman, clergyman and early radio evangelist
* Carol Mann, golfer
* Jamie Miller, drummer Bad Religion
* Jim McKay, ABC-TV sportscaster
* Sid Meier, businessman and computer programmer.
* John Merryman, Civil War militia officer, Maryland politician, and subject of the landmark habeas corpus case, Ex parte Merryman
* Glenn Milstead, known as the actor "Divine"
* Mo'Nique, American comedian and actress
* Jim Palmer, former Baltimore Oriole and Hall of Fame pitcher
* Michael Phelps, Olympic Gold-Medalist swimmer
* Rosa Ponselle, opera singer
* Robin Quivers, radio personality
* Ross Rawlings, pianist, composer, conductor, and music director
* Angel Reese, women's basketball player
* Charles Carnan Ridgely (1760–1829), governor of Maryland and master of the Hampton estate
* Eliza Ridgely (1803–1867), third mistress of the Hampton estate and the subject of the well-known portrait painting Lady with a Harp
* Brooks Robinson, former Baltimore Oriole and Hall of Fame third baseman
* Mike Rowe, TV show host for Dirty Jobs
* Don Shula, Former Baltimore Colts player and later coach of the Miami Dolphins
* Dick Szymanski, former Colts player
* Pam Shriver, professional tennis player, Olympic Gold Medalist in tennis
* Kathleen Kennedy Townsend, politician and member of the Kennedy family
* Gus Triandos, former Baltimore Oriole
* Bob Turley, former major league baseball pitcher
* Johnny Unitas, former Baltimore Colt and Hall of Fame quarterback
* Nikolai Volkoff, former professional wrestler and member of the WWE Hall of Fame
* Daniel Bashiel Warner, third President of Liberia
* John Waters, filmmaker
* Cheryl Wheeler, singer-songwriter
* Ella B. Ensor Wilson (1838–1913), social reformer