Composition of Congress Since 1867

L. David Roper (roperld@vt.edu)

(Back to Politics)

The web site (http://clerkweb.house.gov/elections/1998/TABLE.HTM [Scroll to the bottom.]) for the Clerk of the House of Representatives gives the composition by party of the Congress from the 40th to the 106th Congress. I have added the Presidents according to party.

(Go to the data tables at the bottom.)

This shows the composition of the House of Representatives for Congress numbers from the 40th (1867-1869) to the 106th (1999-2001).
This shows the composition of the Senate for Congress numbers from the 40th (1867-1869) to the 106th (1999-2001).
This shows whether a president was a Democrat (value 1) or Republican (value 0) for Congress numbers from the 40th (1867-1869) to the 106th (1999-2001).
This shows the fraction of Democrats in the House and Senate for Congress numbers from the 40th (1867-1869) to the 106th (1999-2001).

The following tables show the correlation coefficients for the Senate, House and president being Democratic over time. I used Microsoft Excel to calculate the correlation coefficients. The help file for MS Excel describes how to interpret the correlations coefficients: "You can use the Correlation tool to determine whether two ranges of data move together — that is, whether large values of one set are associated with large values of the other (positive correlation), whether small values of one set are associated with large values of the other (negative correlation), or whether values in both sets are unrelated (correlation near zero). "

Correlations 1867-2000 President (Dem=1, Rep=0) Senate Dem/Rep House Dem/Rep
President (Dem=1, Rep=0) 1
Senate Dem/Rep 0.507 1
House Dem/Rep 0.332 0.750 1
Correlations 1929-2000 President (Dem=1, Rep=0) Senate Dem/Rep House Dem/Rep
President (Dem=1, Rep=0) 1
Senate Dem/Rep 0.408 1
House Dem/Rep 0.243 0.798 1

Thus we see that the Senate and House being Democratic for the same congress was highly correlated, that the Senate and president being Democratic for the same congress was somewhat less correlated, and that the House and president being Democratic for the same congress was even less correlated. However, all correlations were positive.

Another way to ascertain the political party control of the U.S. government is to assign the following government party control index:

The following graph compares the Democratic party control index to the Democratic party control of the presidency.

Note that, of the Republican administrations, only the Hoover administration and the first year of the Eisenhower administration had full Republican control of the government. Conversely, in the Democratic administrations, full Democratic control was usually the rule, with the exceptions of the early years and the last year of the Truman administration, the last year of the Carter administration and all but the first year of the Clinton administration.
The above statements are perhaps a little clearer in the graph if one plots the Democratic control of the Congress and the presidency control, instead of the total government control.
This shows the number of years each Democratic party control index value existed for the 101 years 1900-2000. The Democrats had full control for 32 years and the Republicans had full control for 23 years. The Democrats had control of both the House and Senate for 22 years during Republican presidencies. The Republicans had control of both the House and Senate for 10 years during Democratic presidencies.

Yet another way to quantify the Democratic party control is by a Democrat Control Variable. Both the Democrat Control Index and the Democratic Control Variable are shown in the table below.

Political divisions of the U.S. Senate and House of Representatives from 1867 (40th Cong.) to 2000 (106th Cong.)
[ALL FIGURES REFLECT IMMEDIATE RESULT OF ELECTIONS]
Congress Years Senate House of Representatives President Congress Years
Number of Senators Democrats Republicans Other parties Vacant Number of Representatives Democrats Republicans Other parties Vacant Democrats Republicans President (Dem=1, Rep=0) Senate Dem/Rep House Dem/Rep Senate Dem Fraction House Dem Fraction
40th 1867–1869 53 11 42 - - 193 49 143 - 1 0 Johnson 0 0.262 0.343 0.208 0.254 40th 1867–1869
41st 1869–1871 74 11 61 - 2 243 73 170 - 0 Grant 0 0.180 0.429 0.149 0.300 41st 1869–1871
42d 1871–1873 74 17 57 - - 243 104 139 - 0 Grant 0 0.298 0.748 0.230 0.428 42d 1871–1873
43d 1873–1875 74 19 54 - 1 293 88 203 - 2 0 Grant 0 0.352 0.433 0.257 0.300 43d 1873–1875
44th 1875–1877 76 29 46 - 1 293 181 107 3 2 0 Grant 0 0.630 1.692 0.382 0.618 44th 1875–1877
45th 1877–1879 76 36 39 1 - 293 156 137 - 0 Hayes 0 0.923 1.139 0.474 0.532 45th 1877–1879
46th 1879–1881 76 43 33 - - 293 150 128 14 1 0 Hayes 0 1.303 1.172 0.566 0.512 46th 1879–1881
47th 1881–1883 76 37 37 2 - 293 130 152 11 0 Garfield/Arthur 0 1.000 0.855 0.487 0.444 47th 1881–1883
48th 1883–1885 76 36 40 - - 325 200 119 6 0 Arthur 0 0.900 1.681 0.474 0.615 48th 1883–1885
49th 1885–1887 76 34 41 - 1 325 182 140 2 1 Cleveland 1 1 0.829 1.300 0.447 0.560 49th 1885–1887
50th 1887–1889 76 37 39 - - 325 170 151 4 Cleveland 1 1 0.949 1.126 0.487 0.523 50th 1887–1889
51st 1889–1891 84 37 47 - - 330 156 173 1 0 Harrison 0 0.787 0.902 0.440 0.473 51st 1889–1891
52d 1891–1893 88 39 47 2 - 333 231 88 14 0 Harrison 0 0.830 2.625 0.443 0.694 52d 1891–1893
53d 1893–1895 88 44 38 3 3 356 220 126 10 Cleveland 1 1 1.158 1.746 0.500 0.618 53d 1893–1895
54th 1895–1897 88 39 44 5 - 357 104 246 7 Cleveland 1 1 0.886 0.423 0.443 0.291 54th 1895–1897
55th 1897–1899 90 34 46 10 - 357 134 206 16 1 0 McKinley 0 0.739 0.650 0.378 0.375 55th 1897–1899
56th 1899–1901 90 26 53 11 - 357 163 185 9 0 McKinley 0 0.491 0.881 0.289 0.457 56th 1899–1901
57th 1901–1903 90 29 56 3 2 357 153 198 5 1 0 Roosevelt 0 0.518 0.773 0.322 0.429 57th 1901–1903
58th 1903–1905 90 32 58 - - 386 178 207 - 1 0 Roosevelt 0 0.552 0.860 0.356 0.461 58th 1903–1905
59th 1905–1907 90 32 58 - - 386 136 250 - 0 Roosevelt 0 0.552 0.544 0.356 0.352 59th 1905–1907
60th 1907–1909 92 29 61 - 2 386 164 222 - 0 Roosevelt 0 0.475 0.739 0.315 0.425 60th 1907–1909
61st 1909–1911 92 32 59 - 1 391 172 219 - 0 Taft 0 0.542 0.785 0.348 0.440 61st 1909–1911
62d 1911–1913 92 42 49 - 1 391 228 162 1 0 Taft 0 0.857 1.407 0.457 0.583 62d 1911–1913
63d 1913–1915 96 51 44 1 - 435 290 127 18 Wilson 1 1 1.159 2.283 0.531 0.667 63d 1913–1915
64th 1915–1917 96 56 39 1 - 435 231 193 8 3 Wilson 1 1 1.436 1.197 0.583 0.531 64th 1915–1917
65th 1917–1919 96 53 42 1 - 435 210 216 9 Wilson 1 1 1.262 0.972 0.552 0.483 65th 1917–1919
66th 1919–1921 96 47 48 1 - 435 191 237 7 Wilson 1 1 0.979 0.806 0.490 0.439 66th 1919–1921
67th 1921–1923 96 37 59 - - 435 132 300 1 2 0 Harding 0 0.627 0.440 0.385 0.303 67th 1921–1923
68th 1923–1925 96 43 51 2 - 435 207 225 3 0 Harding/Coolidge 0 0.843 0.920 0.448 0.476 68th 1923–1925
69th 1925–1927 96 40 54 1 1 435 183 247 5 0 Coolidge 0 0.741 0.741 0.417 0.421 69th 1925–1927
70th 1927–1929 96 47 48 1 - 435 195 237 3 0 Coolidge 0 0.979 0.823 0.490 0.448 70th 1927–1929
71st 1929–1931 96 39 56 1 - 435 163 267 1 4 0 Hoover 0 0.696 0.610 0.406 0.375 71st 1929–1931
72d 1931–1933 96 47 48 1 - 435 216 218 1 0 Hoover 0 0.979 0.991 0.490 0.497 72d 1931–1933
73d 1933–1935 96 59 36 1 - 435 313 117 5 Roosevelt 1 1 1.639 2.675 0.615 0.720 73d 1933–1935
74th 1935–1937 96 69 25 2 - 435 322 103 10 Roosevelt 1 1 2.760 3.126 0.719 0.740 74th 1935–1937
75th 1937–1939 96 75 17 4 - 435 333 89 13 Roosevelt 1 1 4.412 3.742 0.781 0.766 75th 1937–1939
76th 1939–1941 96 69 23 4 - 435 262 169 4 Roosevelt 1 1 3.000 1.550 0.719 0.602 76th 1939–1941
77th 1941–1943 96 66 28 2 - 435 267 162 6 Roosevelt 1 1 2.357 1.648 0.688 0.614 77th 1941–1943
78th 1943–1945 96 57 38 1 - 435 222 209 4 Roosevelt 1 1 1.500 1.062 0.594 0.510 78th 1943–1945
79th 1945–1947 96 57 38 1 - 435 243 190 2 Roosevelt/Truman 1 1 1.500 1.279 0.594 0.559 79th 1945–1947
80th 1947–1949 96 45 51 - - 435 188 246 1 Truman 1 1 0.882 0.764 0.469 0.432 80th 1947–1949
81st 1949–1951 96 54 42 - - 435 263 171 1 Truman 1 1 1.286 1.538 0.563 0.605 81st 1949–1951
82d 1951–1953 96 48 47 1 - 435 234 199 2 Truman 1 1 1.021 1.176 0.500 0.538 82d 1951–1953
83d 1953–1955 96 46 48 2 - 435 213 221 1 0 Isenhower 0 0.958 0.964 0.479 0.490 83d 1953–1955
84th 1955–1957 96 48 47 1 - 435 232 203 - 0 Isenhower 0 1.021 1.143 0.500 0.533 84th 1955–1957
85th 1957–1959 96 49 47 - - 435 234 201 - 0 Isenhower 0 1.043 1.164 0.510 0.538 85th 1957–1959
86th 1959–1961 98 64 34 - - 436 283 153 - 0 Isenhower 0 1.882 1.850 0.653 0.649 86th 1959–1961
87th 1961–1963 100 64 36 - - 437 262 175 - Kennedy 1 1 1.778 1.497 0.640 0.600 87th 1961–1963
88th 1963–1965 100 67 33 - - 435 258 176 - 1 Kennedy/Johnson 1 1 2.030 1.466 0.670 0.593 88th 1963–1965
89th 1965–1967 100 68 32 - - 435 295 140 - Johnson 1 1 2.125 2.107 0.680 0.678 89th 1965–1967
90th 1967–1969 100 64 36 - - 435 248 187 - Johnson 1 1 1.778 1.326 0.640 0.570 90th 1967–1969
91st 1969–1971 100 58 42 - - 435 243 192 - 0 Nixon 0 1.381 1.266 0.580 0.559 91st 1969–1971
92d 1971–1973 100 54 44 2 - 435 255 180 - 0 Nixon 0 1.227 1.417 0.540 0.586 92d 1971–1973
93d 1973–1975 100 56 42 2 - 435 242 192 1 0 Nixon 0 1.333 1.260 0.560 0.556 93d 1973–1975
94th 1975–1977 100 61 37 2 - 435 291 144 - 0 Nixon/Ford 0 1.649 2.021 0.610 0.669 94th 1975–1977
95th 1977–1979 100 61 38 1 - 435 292 143 - Carter 1 1 1.605 2.042 0.610 0.671 95th 1977–1979
96th 1979–1981 100 58 41 1 - 435 277 158 - Carter 1 1 1.415 1.753 0.580 0.637 96th 1979–1981
97th 1981–1983 100 46 53 1 - 435 242 192 1 0 Reagan 0 0.868 1.260 0.460 0.556 97th 1981–1983
98th 1983–1985 100 46 54 - - 435 269 166 - 0 Reagan 0 0.852 1.620 0.460 0.618 98th 1983–1985
99th 1985–1987 100 47 53 - - 435 253 182 - 0 Reagan 0 0.887 1.390 0.470 0.582 99th 1985–1987
100th 1987–1989 100 55 45 - - 435 258 177 - 0 Reagan 0 1.222 1.458 0.550 0.593 100th 1987–1989
101st 1989–1991 100 55 45 - - 435 260 175 - 0 Bush 0 1.222 1.486 0.550 0.598 101st 1989–1991
102d 1991–1993 100 56 44 - - 435 267 167 1 0 Bush 0 1.273 1.599 0.560 0.614 102d 1991–1993
103d 1993–1995 100 57 43 - - 435 258 176 1 Clinton 1 1 1.326 1.466 0.570 0.593 103d 1993–1995
104th 1995–1997 100 48 52 - - 435 204 230 1 Clinton 1 1 0.923 0.887 0.480 0.469 104th 1995–1997
105th 1997–1999 100 45 52 - - 435 207 226 2 Clinton 1 1 0.865 0.916 0.450 0.476 105th 1997–1999
106th 1999–2001 100 45 52 - - 435 211 223 1 Clinton 1 1 0.865 0.946 0.450 0.485 106th 1999–2001
107th 2001-2003 100 50 50 435 212 221 2 0 BushGW
108th 2003-2005 100 48 51 1 435 204 229 1 0 BushGW
109th 2005-2007 100 44 55 1 435 202 232 1 0 BushGW
110th 2007-2009 100 49 49 2 435 0 BushGW
Congress Years Senate House of Representatives President Congress Years
Number of Senators Democrats Republicans Other parties Vacant Number of Representatives Democrats Republicans Other parties Vacant Democrats Republicans President (Dem=1, Rep=0) Senate Dem/Rep House Dem/Rep Senate Dem Fraction House Dem Fraction