Average Years of Service for Members of the
Senate and House of Representatives,
1st - 111th Congresses
Matthew Eric Glassman
Analyst on the Congress
Erin Hemlin
Research Associate
November 2, 2010
Congressional Research Service
7-5700
www.crs.gov
RL32648
CRS Report for Congress
P
repared for Members and Committees of Congress

---

Average Years of Service for Members of the Senate and House of Representatives

Summary
The average tenure of Members of the Senate and House of Representatives at the beginning of each
Congress has varied substantially since 1789. The purpose of this report is to provide a Congress-by-
Congress summary of the average years of service for Senators and Representatives for the First through
the 111th Congresses. The information for each Congress reflects only the Members entitled to be seated at
the beginning of that Congress.
The report contains a brief summary of some of the explanations by political scientists and others
for the various changes in the average years of service. The information should be read with the
understanding that the length of congressional careers has also depended on the number of
congressional retirements as well as the success rates for those incumbents who have sought
reelection. For information on the number of freshmen elected to Congress, refer to CRS Report
R41283, First-Term Members of the House of Representatives and Senate, 64th – 111th
Congresses, by Jennifer E. Manning and R. Eric Petersen.
The average years of service for Members of the 111th Congress, as of January 3, 2009, when the
Congress convened was 10.1 years for the House and 12.3 years for the Senate.
This report will be updated after the commencement of the 112th Congress.

Congressional Research Service

---

Average Years of Service for Members of the Senate and House of Representatives


Contents
Introduction ................................................................................................................................ 1
Analysis of Data ......................................................................................................................... 2
House of Representatives ...................................................................................................... 2
Senate ................................................................................................................................... 3

Figures
Figure 1. Average Years of Service for Senators and Representatives, by Chamber and
Congress, First - 111th Congresses ............................................................................................ 4

Tables
Table 1. Average Years of Service for Members of the Senate and House of
Representatives, First – 111th Congresses.................................................................................. 5

Contacts
Author Contact Information ........................................................................................................ 8

Congressional Research Service

---

Average Years of Service for Members of the Senate and House of Representatives

Introduction
During the early history of Congress, turnover in membership was frequent, and resignations
were commonplace. Although the Constitution provides that U.S. Senators serve for a term of six
years, it was not until the 50th Congress (1887-1889) that the average tenure of Senators reached
six years. While the average service of Members of the House began to exceed their two-year
term by the Fourth Congress (1795-1797), it did not rise above four years until the 57th Congress
(1901-1903). According to political scientist Randall Ripley, “In the pre-modern Congress,
Members came and went rapidly. There were few senior members. Life in Washington was not
pleasant; Congress did not seem very important, and the unstable party situation often made re-
election difficult to achieve.”1
Most lawmakers in the 18th and early 19th century can be characterized as “citizen legislators,”
holding full-time non-political employment and serving in Congress on a part-time basis for a
short number of years. Political scientist H. Douglas Price wrote that “the distinguished Senators
of the 1st Congress set the early career pattern for that chamber: They fled the Capitol ... almost as
fast as humanly possible.... Career data on the early Senate is a morass of resignations, short-term
appointees, elective replacements.... There are no notable careers in terms of service.”2 According
to Price, the lack of incentives for Members to retain their seats explains the high turnover in
those early years of the House. Power was fluid in the House. The Speaker controlled committee
appointments; there was frequent change in party control, and no seniority influence.3 Price also
wrote that the Congress elected in 1900 was the first in American history in which new Members
accounted for less than 30% of the membership.4
After the 1880s, circumstances changed and the rise of careerism in Congress began in the period
from 1890-1910.5 The strengthening of the party system, the emergence of one-party states and
districts following the Civil War, and institutional changes in Congress made re-election easier.
The emergence of national problems raised a legislative career to a new level of importance; and
the demonstration by Congress, after Lincoln’s death, that it intended to play a more assertive role
in government contributed to many Members’ desire to remain in Congress.6 Subsequently,
legislative careers became professionalized, and the concept of the “citizen legislator” became a
thing of the past.7
Some political scientists and others have attributed the demise of the “citizen legislator” and the
stabilization of congressional membership to (1) the importance of the seniority system; (2)
increased opportunities for junior Members; (3) the ease of traveling between Washington, DC,
and home states and districts; (4) senior Members’ involvement and success in promoting

1 Randall B. Ripley, Congress: Process and Policy, 4th ed. (New York: W.W. Norton and Company, 1988), p. 50.
2 H. Douglas Price, “Congress and the Evolution of Legislative ‘Professionalism,’” in Norman Ornstein, ed., Congress
in Change (New York: Praeger Publishers, 1995), p. 5.
3 Ibid., p. 16.
4 Ibid.
5 David Brady, Kara Buckley, and Douglas Rivers (Stanford University), “The Roots of Careerism in the House of
Representatives,” Legislative Studies Quarterly, vol. 24, November 1999, p. 490.
6 Ripley, Congress: Process and Policy, p. 51; and Price, “Congress and the Evolution of Legislative
‘Professionalism,’” p. 9.
7 Howard Baker, “‘Citizen Legislators’ Would Be Better,” Washington Post, July 8, 1983, p. 21; and Saul Pett, “Baker
Seeks to Change Face of Congress,” Los Angeles Times, August 21, 1983, pp. 2, 15.
Congressional Research Service
1

---

Average Years of Service for Members of the Senate and House of Representatives

legislative agendas; and (5) the advantages of incumbency that allow Members to generate
publicity, serve constituents, and receive support in organizing their offices and forming agendas
that help them be effective legislators.8
In recent years, the fluctuations in congressional service averages cannot be attributed to any
single factor. Self-imposed term limits, retirements, election defeats, and redistricting have all
been factors.9
Analysis of Data
Table 1 shows, by chamber and by Congress, the average years of service at the beginning of
each Congress. Figure 1 graphically plots the data from the First to 111th Congress. The freshmen
Members of each house are counted as having no service (zero years). Changes in membership
during a Congress are not taken into account.
House of Representatives
Between the Second and 12th Congresses (1791-1813), the average years of service for a Member
of the House ranged from a low of 1.0 years to a high of 3.7 years. From the 13th Congress to the
47th Congress (1813-1883), the average service fluctuated from a low of 1.4 years in the 33rd
Congress (1853-1855) to a high of 3.3 years in the 20th Congress (1827-1829). From the 48th
through the 69th Congresses (1883-1927), the average was between 2.4 years and 5.8 years. In the
70th through the 72nd Congresses (1927-1933) during the Great Depression, the average years of
service rose to an all-time high, to that point, of around seven years of service.
One of the highest levels of turnover in the 20th century occurred in the Franklin D. Roosevelt
landslide election of 1932, and in succeeding congressional election cycles as Republicans began
to regain seats lost in 1932. In the 73rd through the 76th Congresses (1933-1941), the average
length of House service fell below six years before trending upward (with some fluctuations) over
the next 65 years.
From the 84th through the 101st Congresses (1955-1991), service ranged from then record highs of
eight to more than nine years, with the exception of the 96th through the 98th Congresses (1979-
1985), when service was somewhat more than seven years. In the 102nd Congress (1991-1993),
the average House service reached an all-time high of 10.2 years. The average length of service
then fluctuated between eight and nine years from the 103rd to the 109th Congresses (1993-2005),
except for the 104th and 105th Congresses (1995-1999), when the change in party control saw the
average service decline to 7.7 years. Since the 109th Congress, the average years of service has
been greater than 10 years.

8 Ibid., and John R. Hibbing, “The Modern Congressional Career,” The American Political Science Review, vol. 85,
June 1991, p. 425.
9 For additional studies on congressional service, see Nelson Polsby, “The Institutionalization of the U.S. House of
Representatives,” The American Political Science Review, vol. 41, March 1968; and Robert G. Brookshire and Dean F.
Duncan, “Congressional Career Patterns and Party Systems,” Legislative Studies Quarterly, vol. VIII, February 1983,
pp. 65-78.
Congressional Research Service
2

---

Average Years of Service for Members of the Senate and House of Representatives

Senate
Between the Second and 21st Congresses (1791-1831), the average years of Senate service ranged
from a low of 1.3 years (Second Congress) to a high of 4.3 years (21st Congress). From the 22nd
Congress though the 48th Congress (1831-1885), the years of Senate service averaged over three
and under five. With the exception of the 62nd and 63rd Congresses (1911-1915), when the average
length of Senate service was about five years, the years of service from the 49th through the 75th
Congresses (1885-1939) averaged between six and seven and one-half years, an indication that
many Senators were beginning to serve more than one term. Note that the direct election of
Senators began with the elections to the 63rd Congress (1913-1915).
From the 76th through the 79th Congresses (1939-1947), Senate service was at a then all-time high
of eight years and has never fallen to five years again. With the change in party control at the
beginning of the 80th Congress (1947-1949), however, it did fall to 6.2 years, before trending
upward from the 84th through the 94th Congresses (1949-1977). Average Senate service passed the
10-year mark in the 90th Congress (1967-1969), as well as the 92nd through 94th Congresses
(1971-1977).
From the 95th through the 100th Congresses (1977-1989), Senate service fluctuated between a
high of 9.6 years in the 100th Congress (1997-1989) and a low of 7.5 years in the 97th Congress
(1981-1983), then remained between 9.9 and 11.8 years from the 101st through the 108th
Congresses (1989-2005). Average Senate service reached record highs in the 108th,109th, and
110th Congresses (2003-2009) with 11.8 years, 12.3 years, and 12.8 years of service, respectively.


Congressional Research Service
3

---

Figure 1. Average Years of Service for Senators and Representatives,
by Chamber and Congress, First - 111th Congresses
14
12
10
8
rs
Senate
a
Ye
6
House
4
2
0
10
20
30
40
50
60
70
80
90
100
110
Congress

Source: CRS analysis of ICPSR and proprietary data.

CRS-4

---

Average Years of Service for Members of the Senate and House of Representatives

Table 1. Average Years of Service for Members of the Senate and House of
Representatives, First – 111th Congresses
Congress and Years
House
Senate
1st, 1789-1791
0.0
0.0
2nd, 1791-1793
1.0
1.3
3rd, 1793-1795
1.2
1.8
4th, 1795-1797
2.0
1.9
5th, 1797-1799
1.9
1.9
6th, 1799-1801
2.3
2.5
7th, 1801-1803
2.3
2.6
8th, 1803-1805
2.1
2.3
9th, 1805-1807
2.7
2.4
10th, 1807-1809
3.0
2.9
11th, 1809-1811
3.3
3.0
12th, 1811-1813
3.7
3.4
13th, 1813-1815
2.6
3.0
14th, 1815-1817
2.9
2.3
15th, 1817-1819
1.7
2.1
16th, 1819-1821
2.1
2.4
17th, 1821-1823
2.2
3.0
18th, 1823-1825
2.4
3.8
19th, 1825-1827
2.8
3.5
20th, 1827-1829
3.3
4.0
21st, 1829-1831
3.1
4.3
22nd, 1831-1833
3.1
3.9
23rd, 1833-1835
2.4
3.4
24th, 1835-1837
2.3
3.2
25th, 1837-1839
2.2
3.5
26th, 1839-1841
2.3
4.2
27th, 1841-1843
2.5
4.0
28th, 1843-1845
1.5
3.9
29th, 1845-1847
1.7
3.7
30th, 1847-1849
2.0
3.7
31st, 1849-1851
1.8
3.7
32nd, 1851-1853
1.6
3.4
33rd, 1853-1855
1.4
3.1
34th, 1855-1857
1.6
3.8
35th, 1857-1859
2.1
4.1
Congressional Research Service
5

---

Average Years of Service for Members of the Senate and House of Representatives

Congress and Years
House
Senate
36th, 1859-1861
2.0
4.6
37th, 1861-1863
1.7
3.7
38th, 1863-1865
1.5
3.6
39th, 1865-1867
2.0
4.0
40th, 1867-1869
2.2
3.7
41st, 1869-1871
2.0
3.3
42nd, 1871-1873
2.1
4.0
43rd, 1873-1875
2.1
4.0
44th, 1875-1877
1.8
3.5
45th, 1877-1879
2.1
4.0
46th, 1879-1881
2.4
4.1
47th, 1881-1883
3.0
4.0
48th, 1883-1885
2.4
4.7
49th, 1885-1887
2.8
5.3
50th, 1887-1889
3.1
6.1
51st, 1889-1891
3.4
6.4
52nd, 1891-1893
2.9
6.7
53rd, 1893-1895
3.2
7.1
54th, 1895-1897
2.5
7.3
55th, 1897-1899
3.1
6.9
56th, 1899-1901
3.5
6.5
57th, 1901-1903
4.0
7.3
58th, 1903-1905
4.0
7.6
59th, 1905-1907
4.8
7.3
60th, 1907-1909
5.0
7.0
61st, 1909-1911
5.5
6.2
62nd, 1911-1913
5.0
4.8
63rd, 1913-1915
4.1
4.8
64th, 1915-1917
4.8
5.9
65th, 1917-1919
5.3
5.7
66th, 1919-1921
5.2
6.4
67th, 1921-1923
5.1
6.4
68th, 1923-1925
5.2
6.1
69th, 1925-1927
5.8
6.0
70th, 1927-1929
6.8
6.6
71st, 1929-1931
7.1
6.8
72nd, 1931-1933
7.3
6.9
Congressional Research Service
6

---

Average Years of Service for Members of the Senate and House of Representatives

Congress and Years
House
Senate
73rd, 1933-1935
5.5
6.9
74th, 1935-1937
5.3
6.9
75th, 1937-1939
5.6
7.0
76th, 1939-1941
5.7
7.9
77th, 1941-1943
6.3
7.1
78th, 1943-1945
6.4
7.6
79th, 1945-1947
6.9
6.6
80th, 1947-1949
6.7
6.2
81st, 1949-1951
6.8
6.3
82nd, 1951-1953
7.4
6.5
83rd, 1953-1955
7.3
6.2
84th, 1955-1957
8.2
7.4
85th, 1957-1959
9.0
8.1
86th, 1959-1961
8.5
7.8
87th, 1961-1963
9.1
8.0
88th, 1963-1965
8.9
8.4
89th, 1965-1967
8.3
9.6
90th, 1967-1969
8.7
10.4
91st, 1969-1971
9.2
9.8
92nd, 1971-1973
9.5
10.5
93rd, 1973-1975
9.0
10.0
94th, 1975-1977
8.4
10.5
95th, 1977-1979
7.9
9.3
96th, 1979-1981
7.7
8.5
97th, 1981-1983
7.3
7.5
98th, 1983-1985
7.4
8.7
99th, 1985-1987
8.3
9.2
100th, 1987-1989
9.0
9.6
101st, 1989-1991
9.5
9.9
102nd, 1991-1993
10.2
10.7
103rd, 1993-1995
8.3
11.0
104th, 1995-1997
7.7
11.1
105th, 1997-1999
7.7
10.3
106th, 1999-2001
8.4
10.9
107th, 2001-2003
9.0
11.0
108th, 2003-2005
9.2
11.8
109th, 2005-2007
10.0
12.3
Congressional Research Service
7

---

Average Years of Service for Members of the Senate and House of Representatives

Congress and Years
House
Senate
110th, 2007-2009
10.0
12.8
111th, 2009-2011
10.1
12.3
Sources: From the 1st through the 101st Congresses (1789-1991), the source was the Inter-University
Consortium for Political and Social Research at the University of Michigan – Ann Arbor, MI (ICPSR). For the
102nd through 111th Congresses (1991-2011), the years were calculated by CRS.


Author Contact Information

Matthew Eric Glassman
Erin Hemlin
Analyst on the Congress
Research Associate
mglassman@crs.loc.gov, 7-3467



Congressional Research Service
8

---