Representatives and Senators: Trends in Member Characteristics Since 1945
Released: 2014-01-27T00:00:00

Questions about the characteristics of Members of Congress, including their age, education, previous occupations, and other descriptors, are of ongoing interest to Members, congressional staff, and constituents. Some of these questions may be asked in the context of representation, in efforts to evaluate the extent to which Members of Congress reflect their constituencies and the nation at large. In other instances, questions arise as to how the characteristics of Members have changed over time, which may speak in part to the history of Congress.

A challenge of discussing Member characteristics in a manner that allows comparison across the history of Congress is the identification of characteristics and reliable data on those characteristics that are collected in a consistent manner over time. No government entity has collected data on Members in a consistent manner for all Congresses. Congressional sources, including entries in the online Biographical Directory of the United States Congress , or the print versions of the biennial Official Congressional Directory , are compiled by the House and Senate, based on information reported by Members. Some academic and journalistic sources provide data on a limited number of Member characteristics over a variety of time periods. While these sources provide some information, they do not report various descriptive characteristics for all Members or all Congresses in a consistent manner. Biographies created by Members for official or campaign purposes are another potential source; those are not readily retrievable for all Members in the Congresses for which this report provides data, and do not report various characteristics for all Members in a uniform manner.

This report provides profiles of Senators and Representatives based on selected characteristics since 1945. Data are drawn from the CQ Press Electronic Library, CQ Congress Collection (hereafter CQ Press), a subscription database that provides data on Members and a range of characteristics. Data provided in this report are based on the number of Representatives and Senators who took seats on the first day of a new Congress. The CQ Press database does not contain information on Members who have served as Delegates or Resident Commissioner for Puerto Rico. Table 1 provides the number of Members who took seats on the first day of the 79 th – 113 th Congresses and the years those Congresses met. The report provides data on the following characteristics: age, including the oldest and youngest Members of the House and Senate; sex; previous occupation; race and ethnicity; education; religion; and military service.

For each characteristic category, a summary is provided. In some categories, the report provides data on the U.S. population that may be comparable to data available on Members of Congress, as discussed in more detail below. Following the characteristic summaries, the report provides a number of tables that provide the detailed data by the category on which the summaries are based. All data tables appear in the " Member Characteristics Data Tables " section.

A detailed discussion of the methods used to develop the data presented in the report, and efforts to provide comparison between Member characteristics and the American public, is provided in an Appendix . Due to differences in data collection or characterization, data in other studies on Member characteristics may differ from those presented in this report.

Characteristics of Representatives and Senators

Age

In general, the ages of Members of Congress and the U.S. population have increased slowly since 1945. Figure 1 provides the median ages of Representatives and Senators in Congresses since 1945, and the U.S. population from the 1940-2010 decennial censuses. Data tables with the mean, or average, and median ages of Members and lists of the oldest and youngest Representatives and Senators, in Congresses since 1945 are provided in the " Age " section, below.

Representatives

In the House, between the 79 th and 98 th Congresses, the ages of Members fluctuated narrowly. The lowest median age in the House, 48.4 years, was recorded in the 98 th Congress. Thereafter, the median age of Representatives began gradually increasing. The 113 th Congress held record highs for the House with median ages of 57.5 years for Representatives.

Senators

The median age of Senators fluctuated narrowly between the 79 th and 97 th Congresses when it reached a low of 51.7 years. The 110 th Congress held a record high for the Senate with a median age of 62.8 years. In the 113 th Congress, the median age of Senators was 61.7 years, a slight change over the previous two Congresses. The median age of the U.S. population in the 2010 census was 37.2 years.

The significant age difference between the U.S. population and Representatives and Senators is explained in part by the scope of people counted in the United States. Census data provide information for all U.S. residents of any age from birth until death. To hold office in the House, the Constitution specifies that a Member must be at least 25 years old. A Senator must be at least 30 years of age. Median ages of Members of Congress are higher than in the U.S. population, since the congressional statistics are calculated on the basis of small numbers of adults in an age-restricted group.

Sex

Until the early 20 th Century, no women served in Congress. Nine decades later, the 113 th Congress has the highest number of female Representatives and Senators ever to serve, but at levels far below that of the general population. Figure 2 provides the distribution of female Members of Congress for Congresses since 1945, the distribution of men and women in each chamber in the 113 th Congress, and the U.S. population, based on the 2010 census. Data on the percentage of female and male Representatives and Senators in Congresses since 1945 are provided in the " Sex " section, below.

The first female to serve in the House, Jeanette Rankin of Montana, was elected to the 65 th Congress (1917-1919). Although no women were elected to the 66 th Congress (1919-1921), during which Congress proposed and the states ratified the 19 th Amendment to the Constitution granting women the right to vote, women have served in the House in every Congress since.

In the Senate, the first female to serve was Rebecca Latimer Felton of Georgia, who was appointed to the Senate on October 3, 1922, following the death of Thomas E. Watson. Aged 87, she served for only 24 hours while the Senate was in session. The next female in the Senate, Hattie Caraway of Arkansas, was appointed on November 13, 1931, to fill the vacancy caused by the death of her husband, Thaddeus H. Caraway. She became the first woman elected to the Senate on January 12, 1932, when she won special election for the remainder of the term and was reelected to two additional terms, serving in the Senate for a total of 14 years. With only a few exceptions, at least one female Senator has served in each Congress since then.

According to the 2010 census, the total population is 50.7% female and 49.3% male. According to the Census Bureau, there have been more females than males in the United States since the 1950 census.

Representatives

The percentage of female Representatives has fluctuated since the 79 th Congress. The House was more than 95% male until the 99 th Congress. The percentage of women doubled, to 10.8%, in the 103 rd Congress, before reaching nearly 15% at the beginning of the 109 th Congress. With a few exceptions—most recently from the 111 th Congress to the 112 th Congress—the percentage of Representatives who are female on the first day of a Congress has generally increased from one Congress to the next.

Senators

Women did not hold 2% of the seats in the Senate until the 87 th Congress, and did not surpass this until the beginning of the 103 rd Congress, when their percentage tripled to 6.0%. The number of female Senators has remained steady or grown ever since, and membership in the 113 th Congress is 20% female.

Previous Occupation

Representatives and Senators bring an array of work experiences with them to Congress. Figure 3 provides a summary of previous occupations of Representatives and Senators in the 113 th Congress.

Since 1945, careers in law and public service are common, but Members have also served as astronauts, entertainers, teachers, and practiced numerous trades. Representatives and Senators have generally similar occupational backgrounds. Most of the occupation data are categorized in the CQ Press data into one of 20 broad subcategories, including, among others: acting/entertainer; business or banking; journalism; law; public service/politics; and real estate.

These and other categories provide a relatively simple way to summarize professional experiences for thousands of diverse Members who have served in Congresses since 1945. It is important to note that the CQ Press data provide an overview of pre-congressional careers, but leave some questions unanswered.

The CQ Press data provide up to five occupational categories for each Representative and Senator. This report provides data on the first—and in some cases, only—occupation provided by CQ Press. In the absence of additional information, however, it is unclear how or why these positions were listed, or why they were listed first when more than one occupation was provided. Finally, in some instances, the CQ Press data provide no information on occupation for some Members.

In addition, the CQ Press data do not provide detail about what facet of a profession a Member pursued, for how long, or whether he or she did so full-time or part-time. In some cases, CQ Press data identify a specific profession, such as Army officer or professor. These listings provide more detail than the broad categories noted above, but might also overlap with some other categories. As discussed above, a former congressional aide might also categorize his or her work as public service/politics. Due to the organization by CQ Press of Members' previously held elective office in a separate category outside the database, the extent of public service backgrounds as the previous occupation of Members may be significantly understated. In summary, it is important to note that this section provides an overview of Member occupation, but the source data do not necessarily reflect all of the occupations Members may have pursued prior to their congressional service.

Representatives

Representatives have diverse occupational backgrounds. As noted above, most primary occupations Representatives reported in the CQ Press data reflect pre-determined categories; others reflect customized titles apparently provided by Members or their staffs. Although the prominence of individual occupations varies by Congress, in general, five occupational categories provided by CQ Press were most commonly reported in the selected Congresses. These include: agriculture; business or banking; congressional aide; education; and law.

Law was the most commonly cited profession over time. Law has not uniformly dominated House Members' professional experience, however. As Figure 4 shows, lawyers dominated among House members between the 79 th and 92 nd Congresses. During that period, approximately 40% of Representatives reported having been part of the legal profession. Beginning in the 102 nd Congress, Representatives listing professional law backgrounds as a primary profession declined sharply, although the occupation continued to be the most common profession cited among Representatives. Even after the 102 nd Congress, at least 20% of Representatives identified law as their first occupation. As Figure 4 shows, as the proportion of House Members with legal experience declined, those reporting occupations in banking or business rose.

Members whose occupations were in banking or business slightly surpassed or were equal to those with legal experience—each group included between roughly 20% and 25% of Representatives—after the 107 th Congresses.

Finally, although careers as congressional aides (which could include a variety of job functions), in agriculture, and education were common overall, they were far less common than business or banking and law. Table 6 provides data on five reported occupations of Representatives in the 79 th – 113 th Congresses.

Senators

Senators in selected Congresses held various professional backgrounds. Senators' occupations, however, have generally been confined to a narrower set of career backgrounds than House Members. Table 7 provides data on five reported occupations of Senators in the 79 th – 113 th Congresses.

Senators' primary occupations generally included agriculture; business or banking; education; or law. These four professional categories are shared with House members, as noted above. There is less certainty about the primary occupation reported fifth-most-frequently.

Senators most frequently cited law and business or banking as their primary professions. Law, in particular, has dominated Senators' occupational experience. As shown, lawyers have occupied between one-third and half of Senate seats in the 79 th – 113 th Congresses. During the 93 rd Congress, Members who had practiced law peaked, with slightly more than half of Senators (54%) identifying their previous occupations in law. Legal backgrounds were less commonly reported in most subsequent Congresses.

Business and banking appeared as the second-most-common occupation. In particular, between approximately 10% and 26% of Senators since 1945 reported having practiced business or banking. Across all Congresses, backgrounds in education have also been common, but far less so than the other most commonly cited jobs. As with the House, Senators' prior professional experience in agriculture has declined steadily over time.

Race and Ethnicity

While recent Congresses have shown some changes, since 1945, the race and ethnicity of Representatives and Senators has been less diverse than that of the general public. Figure 6 compares a distribution of Representatives and Senators by race at the beginning of the 113 th Congress to the U.S. population in the 2010 census.

Representatives

Table 8 provides data on the race and ethnicity of Representatives since 1945. The House of Representatives was more than 95% white until the 93 rd Congress and more than 90% white until the 103 rd Congress. This group comprises 82.2% of the 113 th Congress, a record low. The second largest group is African Americans, who comprised just under 0.5% of the House at the beginning of the 79 th Congress, increasing to a high of 9.7% at the outset of the 112 th Congress, and then decreasing slightly to 9.0% at the outset of the 113 th Congress. This group is followed by the Representatives who have identified as Hispanic, who have grown from 0.2% of the Representatives at the beginning of the 79 th Congress to a record high of 6.7% in the 113 th Congresses. While the 79 th Congress did not have any Asian American Representatives, this group represents 1.8% of the House in the 113 th Congress, also a record high. American Indian membership in the House has fluctuated between 0.0% and 0.2%, which is the current representation in the 113 th Congress.

Senators

Membership of the Senate at the beginning of the 113 th Congress was 95% white, 3% Hispanic, 1% Asian American, and 1% African American. No more than 1% of Senators at the beginning of any Congress identified as African American or Native American. Since 1945, 23 Congresses began with no African American Senators, while there were no Native American Senators at the beginning of 29 Congresses over the same period. Senators identifying as Asian American have ranged between 0% of Senators in the 79 th – 86 th and 88 th Congresses, to a high of 3% of Senators in the 95 th -97 th Congresses. Senators identifying as Hispanic have ranged from 0% (95 th -108 th Congresses) to a high of 3% of Senators at the outset of the 110 th , 111 th , and 113 th Congresses. Table 9 provides data on the race and ethnicity of Senators since 1945.

According to the 2010 Census, the U.S. population is 0.9% "American Indian or Alaska Native"; 4.8% "Asian"; 12.6% "Black or African American"; 16.3% "Hispanic"; 72.4% "White"; 6.2% "Some other race"; and 2.9% "Two or more races." In the 2010 Census data, respondents who identified Hispanic origin also identified a racial category. These data are reported together in Figure 6 . CQ Press identifies Hispanic Members in lieu of specific racial identification. As a consequence of these different data collection methods, direct comparisons of race and ethnicity between Representatives and Senators, and the U.S. population should be made with care.

Education

Since the 79 th Congress, attendance and graduation rates among Representatives and Senators have increased at the high school, college, and graduate levels. Although these rates have also increased among the population at large, the average Member of Congress has a higher educational attainment level than the average American. In the 113 th Congress, the majority of Representatives and Senators have completed high school, college, and some form of graduate school. Today a majority of Americans aged 25 years or older have completed high school, but less than one-third have completed four years of college or attended graduate school.

Historically, most Members of Congress have held at least a high school diploma, and although most Americans today have completed high school, this was not always the case. During the 79 th Congress, the average Member of Congress was more likely to have graduated from high school than the average American. According to the Census Bureau, only 24.1% of American adults age 25 or older had completed four years of high school or more education during the years of the 79 th Congress. By contrast, high school completion rates were 89.2% for House Members and 88.5% for Senators serving in the 79 th Congress. The percentage of those with at least a high school diploma in the United States has since grown, reaching 85.9% in 2011. High school graduation rates among Members of Congress, however, remain at a higher level. In the 113 th Congress, at least 99.77% of Representatives had completed high school, and all Senators had completed high school.

Since 1945, a majority of Representatives and Senators have also held a college degree. The percentage of college graduation rates has increased more markedly since the 79 th Congress than high school graduation rates among Members. Members of Congress also have a higher rate of college attendance and postgraduate education compared to the American population aged 25 years or older. Figure 7 compares the percentages of Representatives, Senators, and the U.S. population with four or more years of college education. The percentage for each group has generally increased since 1945, though a much higher proportion of Senators and Representatives have attended four or more years of college than the U.S. population at large today. Table 10 provides high school and undergraduate college completion data for Representatives in Congresses since 1945. Table 11 provides the same data over the same period for Senators.

During the 79 th Congress, 4.6% of American adults aged 25 years or older completed four or more years of college. In the same time period, 56.3% of Representatives held a bachelor's degree, and 75.0% of Senators held a bachelor's degree. The national average for four or more years of college completed grew to 28.5% in 2011. By the 113 th Congress, however, 92.2% of Representatives, and 97.0% of Senators held a bachelor's degree. In the 113 th Congress, 23 Representatives and one Senator held associate's degrees. For six Representatives, this was the highest degree obtained, but the other Members with associate's degrees also received bachelor's degrees.

The greatest change in Member education since the 79 th Congress has been the increased number of graduate degrees. During the 113 th Congress, 74.4% of Representatives and 74.0% of Senators held graduate degrees. By contrast, only 33.1% of Representatives and 15.6% of Senators held graduate degrees in the 79 th Congress. Both then and now, professional degrees are the most common type of advanced degree held among Representatives and Senators. In the 113 th Congress, 41.6% of Representatives and 56.0% of Senators held professional degrees. 28.9% of Representatives and 18.0% of Senators held master's degrees. Doctoral degrees are fairly rare among Members, with 3.9% of Representatives in the 113 th Congress holding such a degree and no Senators.

Religion

Representatives and Senators have in recent Congresses been more likely to identify affiliation with a religious faith than the public at large. Figure 8 provides a comparison of self-identified religious affiliation among the Representatives and Senators in the 113 th Congress, and the U.S. adult population in 2008, the latest date for which inclusive data are available. Data identifying the reported religious affiliations of Representatives, Senators and the U.S. population during the same periods are provided in Table 13 .

In both chambers, the percentages of Members identifying a religious affiliation grew from the 79 th Congress through the 86 th Congress, remained constant at 97% or higher in the 87 th – 106 th Congresses, and declined slightly thereafter. In the 113 th Congress, 93.6% of Representatives and 91% of Senators identified a religious affiliation. There also have been increases in the number of Members providing information. For example, in the 79 th Congress, CQ Press provided information for 32 Senators and 172 Representatives. In the 113 th Congress, information regarding religious affiliation was specified for 91 Senators and 407 Representatives. Table 12 in the data section provides affiliation data for Representatives and Senators in the 79 th -113 th Congresses.

Religious affiliation data show that Representatives and Senators identify a religious affiliation in higher proportions than that of the general public. Of those who are affiliated, Representatives and Senators identify themselves as Christian or Jewish in greater proportions than those affiliated with those faiths in the U.S. population. Among Christian denominations, Representatives and Senators are affiliated with Catholic, Mormon, and Orthodox churches in greater proportion than the U.S. population. In the 113 th Congress, Representatives are affiliated with Muslim, Buddhist, and Hindu faiths in approximate proportion to the U.S. population. In the Senate, the one adherent of Buddhism represents a greater proportion in that chamber than is present in the U.S. population, although this is magnified by the small number of Senators in comparison to more than the 300 million people who live in the United States. There are no Muslim or Hindu adherents in the Senate.

Representatives

In the 79 th – 113 th Congresses, most Representatives who specified a religious affiliation have identified Christianity or a Christian denomination. The lowest level of Christian identification was 90.3% in the 102 nd Congress; the highest, 97.7%, occurred in the 79 th Congress. Of those Representatives who specified a Christian faith, a majority have identified a Protestant denomination since the 79 th Congress. The Protestant majority peaked in the 82 nd Congress, and has steadily declined, reaching its lowest level in the 113 th Congress at 53.8%. Representatives who identified an affiliation with Judaism ranged from a low of 0.6% in the 79 th Congress, and peaked at 7.7% in the 103 rd Congress. In the 112 th Congress the level is 5.2%.

Table 15 provides affiliation data for Representatives in the 79 th -113 th Congresses. Table 16 provides data on Representatives who identified a Christian denomination.

Senators

Among Senators who identified a religious affiliation, Christianity or a Christian denomination was identified by at least 85% of Senators in each of the selected Congresses. Senators who identified Judaism ranged from zero in the 79 th - 81 st Congresses, increasing to a high of 14% in the 110 th Congress before falling slightly in the 111 th - 113 th Congresses. In the 113 th Congress, Senators who identified a Jewish affiliation comprised 12.09% of those who identified a religion.

Among Senators who identified themselves as Christians, a majority offered a Protestant denomination in each of the selected Congresses. The highest percentage of Protestant Senators occurred in the 82 nd Congress at 88.3%. This level fell steadily through the 113 th Congress, to 51.65%. Table 17 provides affiliation data for Senators in the 79 th – 113 th Congresses. Table 18 provides data on Senators who identified a Christian denomination.

Military Service

Member military service grew gradually following World War II before peaking at 75.2% in the House at the beginning of the 90 th Congress and 80% in the Senate in the 94 th Congress. Thereafter, the total number of veterans declined to 19.6% in the House and 18.1% in the Senate in the 113 th Congress. The number of Representatives in the House who served in the military in the 113 th Congress is up slightly from previous Congresses (18.9% in the 111 th Congress and 17.9% in the 112 th Congress), while the number of Senators who served in the military declined from 26.3% in the 112 th Congress.

Figure 10 illustrates the Representatives, Senators, and members of the U.S. population who have served in the military.

Compared with the general population, Representatives and Senators have served in the military in greater proportions. For example, in the 87 th Congress, 64.3% of Representatives and 68.7% of Senators had served in the military, while only 12.6% of the adult U.S. population were veterans. At the same time, the proportion of Members and the general public who have served may fluctuate in tandem. The percentage of veteran Members increased from the 79 th to the 94 th Congresses and then declined through the 113 th Congress, in a manner that may be similar to the trend seen within the general population. Member military service grew gradually since World War II before peaking at 75.2% in the House in the 90 th Congress, and 78% in the Senate in the 92 nd Congress. Thereafter, the total number of veterans declined to 18% in the House and 27.8% in the Senate in the 111 th Congress. For the 113 th Congress, the number of Members who have served in the military is up slightly in both chambers, with 21.3% of Representatives and 28.9% of Senators having previously served in the armed forces.

Table 19 provides data on the Representatives, Senators and members of the U.S. population who have served in the military.

Compared with the general population, Representatives and Senators have served in the military in greater proportions. For example, in the 79 th Congress, 43.5% of Representatives and 41.3% of Senators had served in the military, while only 3.3% of the adult U.S. population were veterans. Based on limited, comparable data, it appears that it may be the case that the proportion of Members and the general public who have served might fluctuate in tandem. The percentage of veteran Members increased from the 79 th to the 92 nd Congresses and then declined through the 113 th Congress, in a manner similar to service levels seen in the general population.

Concluding Observations

A challenge to understanding an enduring institution like Congress is the broad scope of its activities and the lack of consistent, reliable information about its various components over time. This report focuses on selected characteristics of Members that appear to be consistent over a period of seven decades. Members in 2013 are older, more likely to identify a religious affiliation, and include more women and members of racial and ethnic groups than Members in 1945. The data suggest that since the 79 th Congress, Members have had high levels of education, and worked in professional positions prior to coming to Congress. The number of Members who previously served in the military has risen and fallen, possibly in tandem with the levels of service in the broader population.

These findings arguably provide a more robust understanding of the composition of Representatives and Senators over time than other studies that focus on the membership of individual Congresses. A consistent data source enables longitudinal analysis, but comparisons to other profiles of Congress, which may rely on different data sources, characteristics of Members, or time periods, should be made with caution.

Member Characteristics Data Tables

Data provided in this report include the number of Representatives and Senators who took seats in the House or Senate, respectively, on the first day of a new Congress. Proportions reported may be affected by vacancies. In the 79 th - 85 th Congresses, the Senate had 96 seats representing the 48 states admitted to the Union. During the 86 th Congress the number of seats increased to its current level of 100 with the admission of Alaska and Hawaii as states. Membership of the House has been fixed at 435 seats since 1911, except for a temporary enlargement to 437 in the 86 th – 87 th Congresses to accommodate Representatives from Alaska and Hawaii. The number of House seats reverted to 435 following the 1960 Census and reapportionment. Since CQ Press provides no information on Delegates and the Resident Commissioner from Puerto Rico, they are excluded from House calculations. Table 1 provides the number of Members who took seats on the first day of the 79 th -113 th Congress.

Age

Sex

Previous Occupation

Race/Ethnicity

Education

Religion

Military Service

Appendix. Developing Member Data

Beyond the basic information necessary to ascertain the qualifications for office of a U.S. Senator or Representative, the disclosure of details of a Member's race, education, previous occupation, or other characteristics over the years has been voluntary, and has not been collected by congressional or other governmental authorities. This report provides data on Member characteristics based on sources and methodologies described below.

Member Characteristics

Data on Member characteristics provided in this report are drawn from the CQ Press Electronic Library, CQ Congress Collection (hereafter CQ Press). A subscription database, CQ Press provides data on Members serving since the 79 th Congress and a range of characteristics according to the following variables: Congress; Representative or Senator; political party; state; age; religion; race/ethnicity; previous occupation; sex; and military service. CQ Press provides data on Representatives, Senators, and individuals who served as President and Vice President of the United States. The database does not contain information on Members who have served as Delegates or Resident Commissioner for Puerto Rico.

U.S. population data are based on the results of decennial censuses conducted by the Bureau of the Census between 1940 and 2010, and other official government sources as appropriate. Data on religious affiliations of the U.S. population are taken from a private source, as discussed in the " Religion " section below.

Data for all Representatives and Senators who served on the first day of the 79 th – 113 th Congresses were taken from the CQ Press database. Previously, the material that comprises the CQ Press data was gathered and maintained by Congressional Quarterly, Inc., through research and reporting capacities that now are a part of CQ Roll Call. CQ Press and CQ Roll Call are separate entities with different corporate ownership. Some of the data have been reported in various forms in products created by Congressional Quarterly, Inc., CQ Press, or CQ Roll Call. Those products may also rely on data that are not included in the CQ Congress Collection. Consequently, there may be differences between data reported here and information reported in some commercial products issued by CQ Press, CQ Roll Call and other sources of congressional information.

According to CQ Press, their Member biographical data are derived from a variety of primary sources, including reporting, surveys administered to congressional offices, and official sources. CQ Press reports that it "uses multiple sources to confirm this information, including obituaries and excerpts from major newspapers, as sources do not always agree on precise dates." CQ Press does not indicate whether the data underlying their database have been collected in a consistent manner over time.

In the 79 th – 86 th Congresses, the Senate had 96 seats representing the 48 states admitted to the Union as of the day Congress convened. At the beginning of the 87 th Congress, the number of seats increased to its current level of 100 due to the admission of Alaska and Hawaii as states. Membership of the House has been fixed at 435 seats since 1911, except for a temporary enlargement to 436 in the 86 th Congress (which occurred after the first day) and 437 in the 87 th Congresses to accommodate Representatives from Alaska and Hawaii. The number of House seats reverted to 435 following the 1960 Census and reapportionment that set the distribution of Representatives for the 88 th Congress. On the first day of a new Congress, some seats may be vacant due to the illness or death of a Member-elect, a contested election, or other reason. On the first day of the 111 th Congress in the Senate, for example, 98 Senators were present, and two seats were vacant. In the House, 433 Representatives were present on the first day of the 113 th Congress and two seats were vacant. Percentages provided in figures and data tables above are based on the number of Members who were present on the first day of a Congress in each chamber. Table 1 provides the numbers of Representatives and Senators who took seats in their respective chambers on the first day of the 79 th – 113 th Congresses. Due to differences in data collection or characterization, data in other studies of Member characteristics may differ from those presented in this report.

Comparing Members to the U.S. Population

Comparing the small number of Members of Congress to the population of the United States (131.7 million in 1940; 308.7 million in 2010) poses some challenges. Such challenges results, in part, from differences in scale. Others arise as a consequence of the way information about Members of Congress or the U.S. population is collected, or how the information has been categorized over time. Since, in some instances, described below, there may be no direct comparison between the types of data available describing characteristics of Representatives, Senators and the U.S. population, any comparison between Members and the broader American public is potentially subject to a wide range of interpretations. Conclusions should be drawn from the data provided here with care. Issues that inform the understanding, utility, and comparability of the data presented in this report include the following:

Education

CQ Press data provide the academic degrees Members have earned (high school completion, undergraduate, graduate, and professional degrees). The Census Bureau expresses educational attainment among the U.S. population as percentages of individuals aged 25 years and older who have completed four years of high school or four or more years of college. The Census Bureau also provides a measurement of the median years of schooling completed by the population aged 25 years and older.

Previous Occupation

Questions arise when comparing the occupation of Members to occupations pursued in the United States, but also when comparing the work of Members before they arrived in Congress.

With regard to the comparison of Members to constituents, is the proper comparison between the American public and Members in their roles as government officials, or to the work they did before taking office? In addition, Census and other government efforts to categorize work have changed to reflect the dynamic nature of work activity, which may limit or preclude comparison of occupations over time. Focusing on Member characteristics, what might previous occupations reveal about Members who have served in Congress for many years, or otherwise left other professions to pursue elective office prior to their congressional service? If the focus is on Members in their official capacities, in what ways might that work be categorized?

The CQ Press data provide previous occupations reported by individual Members, organized by broad category identified as "Previous Occupation." Occupations previously practiced by Members might fit into one or more of the subcategories CQ Press identifies. For example, CQ Press provides previous occupational subcategories that include congressional aide, law enforcement, and military; each of these arguably could be included in another subcategory CQ Press provides, entitled "public service/politics." In addition to that concern, the extent to which the public service/politics subcategory includes or excludes Members prior elected service in state or local offices (which are common paths to congressional careers) cannot be determined.

Questions regarding the most appropriate manner of identifying congressional work experience, coupled with changes in the collection of occupational data for the nation, may raise questions about the comparability of congressional and U.S. population data across time. Due to the diversity of employment in the U.S. population, and the challenges of comparing that data to CQ Press information on Members, comparisons between the occupations of Members and those of the U.S. population at large are not provided in this report.

Race and Ethnicity

In the census data, race and ethnicity are currently based on self-identification. CQ Press data, which are collected from a number of sources including self-identification, reports only one response for this category for Members; Members, or other sources, may identify more detailed racial or ethnic affiliations elsewhere. Over time, Congress has required the Census Bureau to deploy a broader array of categories in the decennial censuses, and to allow respondents to choose more than one category. These changes may raise questions about the comparability of congressional and U.S. population data, whether at a specific moment in time or across the span of the Congresses examined.

Religion

Comparing Member religious affiliation to that of the U.S. population poses a number of challenges for several reasons. First, there is no authoritative categorization of American religious practice that covers the period since 1945 in a consistent manner that includes consideration of all faiths, denominations, and traditions. This is due, in part, to the prohibition placed on the Census Bureau from collecting religious affiliation data. Second, the data that are available from private sources for the U.S. population are not readily comparable to the data CQ Press gathers on the religious affiliations of Members of Congress as they chose to identify themselves. CQ Press's Member information includes broad listings that do not identify different traditions within broader denominations. Another challenge is the lack of consistent information on the number of American observers of some religions, or the incomplete collection of data over time. Most efforts to categorize religious affiliation in the United States attempt to identify adherents within the mainline and evangelical traditions of Protestantism, or affiliation with historically Black churches, but no such distinction is possible regarding Member affiliation, based on the CQ Press data. With regard to the U.S. population, it is possible to identify information on the number of Christian adherents in the United States since 1945, but it is more difficult to identify those who follow Jewish, Muslim, Buddhist, or Hindu faiths, or those who identify no religious affiliation. Some of this is explained in part by the preponderance of Americans who identify themselves as Christians, or as members of Christian churches. As a consequence, it is only possible to compare religious adherents in the House and Senate in the 113 th Congress, and the U.S. population in 2008. U.S. population data are based on the research of the Pew Forum on Religious & Public Life.

Military Service

As with previous occupation, questions arise when considering the military service of Members of Congress, or comparing that service to the U.S. population.

Some Members come to Congress after working in other occupations, including having served in military service. Members may continue to serve in the military during their terms of office. CQ Press provides military categories as follows: did not serve, or service in the U.S. Air Force; U.S. Army; U.S. Marine Corps; or U.S. Navy, but does not distinguish whether the service occurred before, during, or after a Member's term of office. Despite its stated categorizations, the CQ Press data provide as military service responses that include reported service in the reserves; state guards and militias; military components (e.g., "ROTC," field artillery, or volunteer infantry); and specific conflicts (e.g., Spanish-American War). In addition, the CQ Press data provide activity that may or may not constitute military service, including work for the U.S. Food Administration and War Trade Board, or the Public Health Service, or service with the "U.S. General Hospital." This report provides data on Members identified in the CQ Press data as having military service regardless of type. As a consequence it is possible that the extent of Member military service may be overstated in some instances.

An additional set of challenges arises when comparing the military service of Members with the service of the general population. Data on the number of Americans serving in the military is not readily available. Military service is a defining characteristic of veteran status, but data on veteran status are also problematic. The statutory definition of veterans appears to exclude service in reserve and state guard units, which precludes comparison between data collected by the Department of Veterans' Affairs for the general population and the CQ Press Member data. Instead, this report relies on data provided by the Census Bureau, which published veteran information in the 1960-2000 decennial censuses, and continues to collect veterans' data through the American Community Survey (ACS). Census data excluded reservists, members of state guards, and women from its tabulations of veterans until 1980, and took steps to clarify veteran status by age, and type of military service, in most censuses. As a consequence, direct comparability between Census Bureau data and the CQ Press data may be problematic, due to data inconsistencies in both collections.