Langbahn Team – Weltmeisterschaft

Party divisions of United States Congresses

Shows partisan status of both Houses of Congress, the Presidency, and the overall trifecta of American Federal Government between 1855-2025. Original work by ChrisnHouston.
Popular vote and house seats won by party

Party divisions of United States Congresses have played a central role on the organization and operations of both chambers of the United States Congress—the Senate and the House of Representatives—since its establishment as the bicameral legislature of the Federal government of the United States in 1789. Political parties had not been anticipated when the U.S. Constitution was drafted in 1787, nor did they exist at the time the first Senate elections and House elections occurred in 1788 and 1789. Organized political parties developed in the U.S. in the 1790s, but political factions—from which organized parties evolved—began to appear almost immediately after the 1st Congress convened. Those who supported the Washington administration were referred to as "pro-administration" and would eventually form the Federalist Party, while those in opposition joined the emerging Democratic-Republican Party.[1]


Party divisions by Congress

The following table lists the party divisions for each United States Congress. Note that numbers in boldface denote the majority party at that particular time while italicized numbers signify a Congress in which the majority party changed intra-term.

Congress Years Senate House of Representatives President Trifecta
Total Anti-
Admin[2] 		Pro-
Admin[3] 		Others Vacancies Total Anti-
Admin 		Pro-
Admin 		Others Vacancies
1st 1789–1791 26 8 18 — — 65 28 37 — — George Washington Yes[4]
2nd 1791–1793 30 13 16 — 1 69 30 39 — — Yes[4]
3rd 1793–1795 30 14 16 — — 105 54 51 — — No
Congress Years Total Democratic-
Republicans 		Federalists Others Vacancies Total Democratic-
Republicans 		Federalists Others Vacancies President Trifecta
4th 1795–1797 32 11 21 — — 106 59 47 — — George Washington[5] No
5th 1797–1799 32 10 22 — — 106 49 57 — — John Adams Yes
6th 1799–1801 32 10 22 — — 106 46 60 — — Yes
7th 1801–1803 34[6] 17 15 — 2 107 68 38 — 1 Thomas Jefferson No/Yes[6]
8th 1803–1805 34 25 9 — — 142 103 39 — — Yes
9th 1805–1807 34 27 7 — — 142 114 28 — — Yes
10th 1807–1809 34 28 6 — — 142 116 26 — — Yes
11th 1809–1811 34 27 7 — — 142 92 50 — — James Madison Yes
12th 1811–1813 36 30 6 — — 143 107 36 — — Yes
13th 1813–1815 36 28 8 — — 182 114 68 — — Yes
14th 1815–1817 38 26 12 — — 183 119 64 — — Yes
15th 1817–1819 42 30 12 — — 185 146 39 — — James Monroe Yes
16th 1819–1821 46 37 9 — — 186 160 26 — — Yes
17th 1821–1823 48 44 4 — — 187 155 32 — — Yes
18th 1823–1825 48 43 5 — — 213 189 24 — — Yes
Congress Years Total Jacksonian[7] Anti-Jackson[7] Others Vacancies Total Jacksonian[7] Anti-Jackson[7] Others Vacancies President Trifecta
19th 1825–1827 48 26 22 — — 213 104 109 — — John Quincy Adams[8] No
20th 1827–1829 48 27 21 — — 213 113 100 — — No
21st 1829–1831 48 25 23 — — 213 136 72 5 — Andrew Jackson Yes
22nd 1831–1833 48[9] 24 22 2 — 213 126 66 21 — Yes[10]
23rd 1833–1835 48 20 26 2 — 240 143 63 34 — No
24th 1835–1837 52 [11] 26 24 2 — 242 143 75 24 — No/Yes[12]
Congress Years Total Democrats Whigs Others Vacancies Total Democrats Whigs Others Vacancies President Trifecta
25th 1837–1839 52 35 17 — — 242 128 100 14 — Martin Van Buren Yes
26th 1839–1841 52 30 22 — — 242 125 109 8 — Yes
27th 1841–1843 52 22 29 — 1 242 98 142 2 — John Tyler[13] Yes/No[14]
28th 1843–1845 52 23 29 — — 223 147 72 4 — No
29th 1845–1847 58 34 22 — 2 228 142 79 7 — James K. Polk Yes
30th 1847–1849 60 38 21 1 — 230[15] 110 116 4 — No
31st 1849–1851 62 35 25 2 — 233 [16] 113 108 11 1 Zachary Taylor[17] No
32nd 1851–1853 62 36 23 3 — 233 127 85 21 — Millard Fillmore No
33rd 1853–1855 62 38 22 2 — 234 157 71 6 — Franklin Pierce Yes
Congress Years Total Democrats Opposition[18] Others Vacancies Total Democrats Opposition Others Vacancies President Trifecta
34th 1855–1857 62 39 21 2 — 234 83 100 51 — Franklin Pierce No
Congress Years Total Democrats Republicans Others Vacancies Total Democrats Republicans Others Vacancies President Trifecta
35th 1857–1859 64 39 20 5 — 237 131 94 13 — James Buchanan Yes
36th 1859–1861 66 38 26 2 — 237 [19] 101 113 23 — No
37th 1861–1863 50 11 31 7 1 178 42 106 28 2 Abraham Lincoln[20] Yes
38th 1863–1865 51 12 29 — — 183 [21] 80 103 — — Yes [22]
39th 1865–1867 52 10 42 — — 191 46 145 — — Andrew Johnson[23] Yes*[24]
40th 1867–1869 53 11 42 — — 193 49 143 — 1 Yes*/No*[24]
41st 1869–1871 74 11 61 — 2 243 73 170 — — Ulysses S. Grant Yes
42nd 1871–1873 74 17 57 — — 243 104 136 3 — Yes
43rd 1873–1875 74 19 54 — 1 293 88 203 — 2 Yes
44th 1875–1877 76 29 46 — 1 293 181 107 3 2 No
45th 1877–1879 76[25] 36 39 1 — 293 156 137 — — Rutherford B. Hayes No
46th 1879–1881 76 43 33 — — 293[26] 150 128 14 1 No
47th 1881–1883 76[27] 37 37 2 — 293[28] 130 152 11 — Chester A. Arthur[29] Yes*[27][30]
48th 1883–1885 76[31] 36 40 — — 325 200 119 6 — No
49th 1885–1887 76[32] 34 41 — 1 325 182 140 2 1 Grover Cleveland No
50th 1887–1889 76[32] 37 39 — — 325 170 151 4 — No
51st 1889–1891 84 37 47 — — 330 156 173 1 — Benjamin Harrison Yes
52nd 1891–1893 88 39 47 2 — 333 231 88 14 — No
53rd 1893–1895 88 [33] 44 38 3 3 356 220 126 10 — Grover Cleveland Yes [34]
54th 1895–1897 88 [35] 39 44 5 — 357 104 246 7 — No
55th 1897–1899 90[36] 34 46 10 — 357 134 206 16 1 William McKinley[37] Yes[38]
56th 1899–1901 90 26 53 11 — 357 163 185 9 — Yes
57th 1901–1903 90 29 56 3 2 357 153 198 5 1 Theodore Roosevelt Yes
58th 1903–1905 90 32 58 — — 386 178 207 — 1 Yes
59th 1905–1907 90 32 58 — — 386 136 250 — — Yes
60th 1907–1909 92 29 61 — 2 386 164 222 — — Yes
61st 1909–1911 92 32 59 — 1 391 172 219 — — William H. Taft Yes
62nd 1911–1913 92 42 49 — 1 391 228 162 1 — No
63rd 1913–1915 96 51 44 1 — 435 290 127 18 — Woodrow Wilson Yes
64th 1915–1917 96 56 39 1 — 435 231 193 8 3 Yes
65th 1917–1919 96 53 42 1 — 435 210 216 9[39] — Yes[40]
66th 1919–1921 96 47 49 — — 435 191 237 7 — No
67th 1921–1923 96 37 59 — — 435 132 300 1 2 Warren G. Harding[41] Yes
68th 1923–1925 96 43 51 2 — 435 207 225 3 — Calvin Coolidge Yes
69th 1925–1927 96 40 54 1 1 435 183 247 5 — Yes
70th 1927–1929 96[42] 47 48 1 — 435 195 237 3 — Yes[43]
71st 1929–1931 96 39 56 1 — 435 163 267 1 4 Herbert Hoover Yes
72nd 1931–1933 96[44] 47 48 1 — 435[45] 217 217 1 — No
73rd 1933–1935 96 59 36 1 — 435 313 117 5 — Franklin D. Roosevelt[46] Yes
74th 1935–1937 96 69 25 2 — 435 322 103 10 — Yes
75th 1937–1939 96 76 16 4 — 435 333 89 13 — Yes
76th 1939–1941 96 69 23 4 — 435 261 169 5 — Yes
77th 1941–1943 96 66 28 2 — 435 268 162 5 — Yes
78th 1943–1945 96 57 38 1 — 435 222 209 4 — Yes
79th 1945–1947 96 57 38 1 — 435 243 190 2 — Harry S. Truman Yes
80th 1947–1949 96 45 51 — — 435 188 246 1 — No
81st 1949–1951 96 54 42 — — 435 262 171 2 — Yes
82nd 1951–1953 96 48 47 1 — 435 235 199 1 — Yes
83rd 1953–1955 96[47] 47 48 1 — 435 213 221 1 — Dwight D. Eisenhower Yes[48][49]
84th 1955–1957 96 [50] 48 47 1 — 435 232 203 — — No
85th 1957–1959 96 49 47 — — 435 234 201 — — No
86th 1959–1961 98 64 34 — — 437 284 153 — — No
87th 1961–1963 100 64 36 — — 437 262 175 — — John F. Kennedy[51] Yes[52]
88th 1963–1965 100 67 33 — — 435 258 176 — 1 Lyndon B. Johnson Yes
89th 1965–1967 100 68 32 — — 435 295 140 — — Yes
90th 1967–1969 100 64 36 — — 435 247 187 — 1 Yes
91st 1969–1971 100 58 42 — — 435 243 192 — — Richard Nixon[53] No[54]
92nd 1971–1973 100 54 44 2 — 435 255 180 — — No
93rd 1973–1975 100 56 42 2 — 435 243 192 — — Gerald Ford No
94th 1975–1977 100 61 37 2 — 435 291 144 — — No
95th 1977–1979 100 61 38 1 — 435 292 143 — — Jimmy Carter Yes[52]
96th 1979–1981 100 58 41 1 — 435 277 157 1[55] — Yes
97th 1981–1983 100 46 53 1 — 435 242 192 1[55] — Ronald Reagan No
98th 1983–1985 100 46/45 54/55 — — 435 269 165 1[55] — No
99th 1985–1987 100 47 53 — — 435 253 181 1[56] — No
100th 1987–1989 100 55 45 — — 435 258 177 — — No
101st 1989–1991 100 55 45 — — 435 260 175 — — George H. W. Bush No
102nd 1991–1993 100 56 44 — — 435 267 167 1[57] — No
103rd 1993–1995 100 57 43 — — 435 258 176 1[57] — Bill Clinton Yes[52]
104th 1995–1997 100 47 53 — — 435 204 230 1[57] — No
105th 1997–1999 100 45 55 — — 435 206 227 2[58] — No
106th 1999–2001 100 45 55 — — 435 211 223 1[57] — No
107th 2001–2003 100 50[59] 50/49[60] 0/1[61] — 435 212 221 2[62] — George W. Bush Yes/No[63]
108th 2003–2005 100 48 51 1[61] — 435 205 229 1[57] — Yes
109th 2005–2007 100 44 55 1[61] — 435 202 232 1[57] — Yes
110th 2007–2009 100 49 49 2[64] — 435 233 202 — — No
111th 2009–2011 100 56–58[65] 40–42[66] 2[64] — 435 257 178 — — Barack Obama Yes[52]
112th 2011–2013 100 51 47 2[64] — 435 193 242 — — No
113th 2013–2015 100 53 45 2[67] — 435 201 234 — — No
114th 2015–2017 100 44 54 2[67] — 435 188 247 — — No
115th 2017–2019 100 46/47 50–52 2[67] — 435 194 241 — — Donald Trump Yes[48]
116th 2019–2021 100 45/46 53/52 2[67] — 435 235 200 — — No
117th 2021–2023 100 46–48[68] 51/50[69] 2/3[70] — 435 222 213 — — Joe Biden Yes[71]
118th 2023–2025 100 47/48 49 3/4[72] — 435 213 221 — 1[73] No
119th 2025–2027 100 45 53 2[67] — 435 215 220 — — Donald Trump Yes[48]
Congress Years Total Democrats Republicans Others Vacancies Total Democrats Republicans Others Vacancies President Trifecta
Senate House of Representatives

Partisan control of Congress

This table shows the number of Congresses in which a party controlled either the House, the Senate, or the presidency.

Party Senate House Presidency Trifecta
Democratic 51 59 45 30
Republican 43 36 46 22[74]
Democratic-
Republican 		12 13 14 12
Federalist 3 2 2 2
Pro-
Administration 		3 2 0 2
Whig 2 2 2 0[75]
National
Republican 		1 1 0 0
Anti-
Administration 		0 1 0 0
Opposition 0 1 0 0
National
Union 		0 0 2 0
Split control 2[76] 0 1[77] 49
Independent 0 0 5 -

See also

References

  1. ^ U.S. Senate: Party Divisions
  2. ^ The Anti-Administration Party was not a formal political party but rather a faction opposed to the policies of Treasury Secretary Alexander Hamilton. The faction eventually coalesced into the Democratic-Republican Party.
  3. ^ The Pro-Administration Party was not a formal political party but rather a faction supportive of the policies of Treasury Secretary Alexander Hamilton. The faction eventually coalesced into the Federalist Party.
  4. ^ a b Though Washington never formally joined a party, he was broadly sympathetic to what was later called the “Pro-Administration” faction which later became the Federalist Party.
  5. ^ Washington disapproved of formal political parties and refused to join either party, though he became a symbol of the Federalist Party.
  6. ^ a b When Democratic-Republican Thomas Jefferson began his Presidency in March 1801 the Senate held a two-day special Senate session with an ongoing Federalist majority, which briefly stalled the inauguration of a Democratic-Republican trifecta government, though the session was only called by outgoing President John Adams so that the Senate could provide advice to the new President. By the time the Congress began its first regular session in December 1801 to start official business the Democratic-Republicans had gained the Senate majority and thus, with the House and with President Jefferson, held the full trifecta of government throughout that first session and for the next several years. "Congressional Record, March 1801" (PDF). Congressional Record: 147–151. March 1801."Explanation of the Types of Sessions of Congress". The Green Papers. June 2001.
  7. ^ a b c d The Democratic-Republican Party broke up into two competing parties during the 1820s, but there is no official date of dissolution for the Democratic-Republicans. During the presidency of John Quincy Adams, Congress became divided between a group that favored Adams and a group that favored Andrew Jackson. After Adams left office, Congress was divided into a group that supported the Jackson administration and a group that opposed it. During Jackson's presidency, the pro-Jackson group coalesced into the Democratic Party, while the anti-Jackson group (which included the National Republican Party) joined with the Anti-Masonic Party and other groups to form the Whig Party.
  8. ^ Adams won election as a Democratic-Republican, but he sought re-election as a National Republican.
  9. ^ Jacksonian control of the Senate was through plurality.
  10. ^ Jackson had a trifecta through a Senate that was controlled by plurality.
  11. ^ In the first Congressional session the Senate remained under control of “National Republicans” for one year; before the start of the second Congressional session the Senate reverted to Jacksonian control, and Jacksonians kept the Senate for the remainder of the Congressional term.
  12. ^ Jackson did not have a trifecta during the first Congressional session when the Senate remained under control of “National Republicans” for one year; Jacksonians flipped the Senate before the second Congressional session and Jackson held a trifecta through that new Senate majority for the remainder of the Congressional term.
  13. ^ Whig President William Henry Harrison died April 4, 1841, one month into his term, and was succeeded by John Tyler, who served for the remainder of the term. Tyler had been elected as vice president on the Whig ticket, but he became an independent after the Whigs expelled him from the party on September 13, 1841.
  14. ^ Whigs held their only trifecta from March 4, 1841, until later that year when the Whigs expelled Tyler from the party on September 13 and he became an Independent.
  15. ^ Whigs controlled the House through a plurality in the 2nd half of the 1st Congressional session; for the remainder of the two sessions the Whigs controlled the House through a majority.
  16. ^ The Democrats held the House through a plurality.
  17. ^ President Taylor died July 9, 1850, about one year and four months into the term, and was succeeded by Millard Fillmore, who served for the remainder of the term.
  18. ^ The "Opposition Party" was the congressional coalition formed by former Whigs and members of the nascent Republican Party. The Opposition Party opposed the Democratic Party in the aftermath of the collapse of the Whig Party.
  19. ^ The Republicans controlled the House through a coalition with other Opposition parties.
  20. ^ President Lincoln was assassinated and died April 15, 1865, about a month after beginning his second term as president. He was succeeded by Democrat Andrew Johnson, who served the remainder of the term.
  21. ^ The Republicans controlled the House through a coalition with Unconditional Unionists.
  22. ^ The Republicans held a trifecta by controlling the House through a coalition with Unconditional Unionists.
  23. ^ Johnson was elected as vice president on the National Union ticket, but was a Democrat prior to the 1864 election.
  24. ^ a b While Lincoln’s successor President Andrew Johnson, elected through the Republican-aligned National Union Party after formerly being a War Democrat, and the Republican Congress were on good terms and cooperated the first few years of his presidency, the relationship grew increasingly strained due to Johnson’s disagreements with Radical Republicans over the nature of Reconstruction. After the midterms, Congress would substantially break with Johnson and begin their first attempt at impeachment against him in January 1867, by which point Johnson’s practical trifecta was gone though he was still a National Unionist for the remainder of the term.
  25. ^ Republicans controlled the Senate through the tie-breaking VP.
  26. ^ Democrats controlled the House through a coalition with Independent Democrats.
  27. ^ a b When the Congressional term began with a special Senate session starting March 1881, the Republicans held the Senate (and a trifecta) through the tie-breaking Vice President Arthur and through a caucus that included a Readjuster Senator. When both Republican New York senators resigned on May 16 of that year, the Republicans lost control of the Senate and lost their trifecta, and the Senate ended their special session. By the time the Senate reconvened for a second special Senate session in October 1881 with two new Republican New York senators, Vice President Arthur had succeeded to the Presidency and the Senate deadlocked in what is known as the "Great Senate Deadlock of 1881”. For the rest of the special session and for the remaining two regular Congressional sessions, the Senate decided to give Republicans the role of controlling the all-too important Senate committees, give the Democrat-caucusing Independent the mostly ceremonial role of president pro tempore, and leave the patronage appointments and other Senate office appointments to the Democrats. "The Great Senate Deadlock of 1881". Senate.gov. US Senate. Retrieved 1 July 2014.
  28. ^ Republicans controlled the House through a plurality that eventually became a majority in the middle of the first Congressional session.
  29. ^ James A. Garfield died September 23, 1881, roughly six months into his term. He was succeeded by Chester Arthur, who served for the remainder of the term.
  30. ^ Republicans held a trifecta through a Republican House plurality that eventually became a majority in the middle of the first Congressional session and through a VP-tie-breaking Senate majority caucus, then held a de facto trifecta through a split Senate where they controlled the all-too important Senate committees.
  31. ^ Republicans controlled the Senate through a caucus with Readjusters.
  32. ^ a b Republicans controlled the Senate through a continued caucus with Readjusters.
  33. ^ Democrats controlled the Senate through a plurality.
  34. ^ Democrats held a trifecta by controlling the Senate through a plurality.
  35. ^ Republicans controlled the Senate through a plurality.
  36. ^ Republicans controlled the Senate through a plurality.
  37. ^ McKinley died September 14, 1901, about six months into his second term, and was succeeded by Theodore Roosevelt. Roosevelt served for the remainder of the term and was elected president in 1904.
  38. ^ Republicans held a trifecta by controlling the Senate through a plurality.
  39. ^ The Democratic Party controlled the House in coalition with the Progressive Party and the Socialist Party. The lone congressional member of the Prohibition Party was not a part of this coalition.
  40. ^ Democrats held a trifecta through a coalition-led House majority with Progressive members and a Socialist member.
  41. ^ President Harding died August 2, 1923, about two years and five months after becoming president, and was succeeded by vice-president Calvin Coolidge. Coolidge served for the remainder of the term and was subsequently elected president in 1924.
  42. ^ At the end of the first month of the first session of Congress, Republicans gained control of the Senate through a VP-tie-breaking majority.
  43. ^ Republicans controlled a trifecta through a VP-tie-breaking majority in the Senate that began at the end of the first month of the first session of Congress.
  44. ^ Republicans controlled the Senate through a VP-tie-breaking majority.
  45. ^ Before Congress’ first session, Democrats gained the House majority, and they held that majority for the entire remainder of the Congressional term.
  46. ^ Roosevelt died April 12, 1945, about three months into his fourth term as president, and was succeeded by Harry S. Truman. Truman served the remainder of the term and was elected president in 1948.
  47. ^ Republicans controlled the Senate for the first Congressional session through a VP-tie-breaking majority (1953), then controlled the Senate for the second congressional session through a VP-tie-breaking majority that included a caucus with an Independent (1954).
  48. ^ a b c According to the 20th Amendment to the U.S. Constitution, the new session of Congress begins on the 3rd of January, while the new presidency begins on the 20th of January. For the first seventeen days of this Congress, both the House of Representatives and the Senate were held by Republican Party, while the outgoing President was of the Democratic Party. After these seventeen days, the Republican Party had a trifecta.
  49. ^ Republicans held a trifecta by controlling the Senate for the first Congressional session through a VP-tie-breaking majority (1953), then controlling the Senate for the second Congressional session through a VP-tie-breaking majority that included a caucus with an Independent (1954).
  50. ^ Democrats controlled the Senate for one year through a caucus with an independent, before the independent joined the Democratic Party (1955).
  51. ^ Kennedy died November 22, 1963, about two years and ten months into the term, and was succeeded by Lyndon B. Johnson. Johnson served the remainder of the term and was elected president in 1964.
  52. ^ a b c d According to the 20th Amendment to the U.S. Constitution, the new session of Congress begins on the 3rd of January, while the new presidency begins on the 20th of January. For the first seventeen days of this Congress, both the House of Representatives and the Senate were held by the Democratic Party, while the outgoing President was of the Republican Party. After these seventeen days, the Democratic Party had a trifecta.
  53. ^ Nixon resigned August 9, 1974, about a year and seven months into his second term as president, and was succeeded by Gerald R. Ford, who served for the remainder of the term.
  54. ^ According to the 20th Amendment to the U.S. Constitution, the new session of Congress begins on the 3rd of January, while the new presidency begins on the 20th of January. For the first seventeen days of this Congress, the Democratic Party had a trifecta. After these seventeen days, both the House of Representatives and the Senate were held by the Democratic Party, while the President Nixon was of the Republican Party.
  55. ^ a b c In the 96th, 97th, and 98th Congresses, the only Conservative member of the House, William Carney of New York, caucused with the Republican Party.
  56. ^ Carney was elected as a Conservative but caucused with Republicans until October 1985, when he joined the Republican Party.
  57. ^ a b c d e f In the 102nd through 109th Congresses, Independent Bernie Sanders of Vermont's at-large congressional district caucused with the Democratic Party.
  58. ^ In the 102nd through 109th Congresses, Independent Bernie Sanders of Vermont caucused with the Democratic Party. Independent Jo Ann Emerson switched to the Republican party on January 8, 1997.
  59. ^ The Democratic Party controlled the Senate in the 107th Congress from January 3 to January 20, 2001 (50-50 tie with Democratic Vice President Al Gore as the deciding vote) and from May 24, 2001, to January 3, 2003 (after Senator Jim Jeffords left the Republican Party to become an Independent and caucus with the Democrats).
  60. ^ The Republican Party controlled the Senate in the 107th Congress from January 20, 2001 (50-50 tie with Republican Vice President Dick Cheney as the deciding vote) until May 24, 2001, when Senator Jim Jeffords left the Republican Party to become an Independent and caucus with the Democrats.
  61. ^ a b c In the 107th Congress (after May 24, 2001), and in the 108th Congress and 109th Congress, Independent Jim Jeffords of Vermont caucused with the Democratic Party.
  62. ^ In the 102nd through 109th Congresses, Independent Bernie Sanders of Vermont caucused with the Democratic Party. Independent Virgil Goode switched to the Republican party on August 1, 2002.
  63. ^ Republicans only held a trifecta from January 20 until May 24, 2001, when Senator Jim Jeffords left the Republican Party to become an Independent and caucus with the Democrats.
  64. ^ a b c Two independent members of the Senate caucused with the Democratic Party, and thus are considered to be a part of the Senate Democratic Caucus. In the 110th, 111th, and 112th Congresses, it was Joseph Lieberman and Bernie Sanders.
  65. ^ From January 27 to April 28, 2009, when Senator Arlen Specter (R-Pennsylvania) joined the Democratic caucus, there were 56 Democratic senators, 41 Republicans, two independents, and one undecided seat in Minnesota. That vacancy was filled as an additional Democratic seat on July 7, 2009, with the swearing-in of Al Franken, bringing the totals to 58 Democrats, 40 Republicans, and 2 independents. Seven weeks later, on August 25, Sen. Edward M. Kennedy (D-Mass.) died, lowering the Democratic total to 57 for a month until Paul G. Kirk Jr. (D) was appointed and sworn in as Senator Kennedy's interim replacement on September 25, 2009. Just over four months later, on February 4, 2010, Scott Brown (R) who had won a special election for the seat, succeeded Paul Kirk, returning the Republican caucus to 41, and again reducing the Democratic caucus to 57 plus two independents. [The Democratic caucus dropped again briefly to 56 in the 18 days between the death of Sen. Robert Byrd (D-West Virginia) on June 28, 2010, and the seating of his interim successor, Carte Goodwin (also D) on July 16.] The appointed Democratic senator from Illinois, Roland Burris was succeeded on November 29, 2010, by Mark Kirk, a Republican elected earlier that month, once again dropping the Democratic caucus to 56 with 2 independents facing 42 Republicans for the last month of the 111th Congress. December 2011 Congressional Directory, page 324
  66. ^ From January 3 to April 28, 2009, prior to Senator Arlen Specter's switch to the Democratic Party, there were 41 Republican senators. The Republican caucus returned to 41 on February 4, 2010, with the swearing in of Scott Brown (R-Mass.) to fill the Democratic seat of Edward Kennedy and Paul Kirk. After Mark Kirk (R-Ill.) replaced Roland Burris as senator from Illinois on November 29, 2010, the Senate in the last month of the 111th Congress stood at 42 Republicans, 56 Democrats, and 2 independents.
  67. ^ a b c d e Two independent members of the Senate caucused with the Democratic Party, and thus are considered to be a part of the Senate Democratic Caucus. In the 113th, 114th, 115th, 116th, 117th, and 119th Congresses, it was Angus King and Bernie Sanders.
  68. ^ The Democratic Party took control of the Senate in the 117th Congress with the swearing in of Democratic senators Raphael Warnock and Jon Ossoff on January 20, 2021. With the two Independent senators (Bernie Sanders and Angus King) caucusing with the Democrats to create a 50-50 tie, Democratic Vice President Kamala Harris became the deciding vote to give Democrats the majority.
  69. ^ The Republican Party controlled the Senate in the 117th Congress from January 3 to January 20, 2021.
  70. ^ In the 117th Congress, Angus King and Bernie Sanders continued to serve as Independent Democrats, and Democratic senator Kyrsten Sinema switched to join them on December 9th, 2022.
  71. ^ Due to Democrats Jon Ossoff and Raphael Warnock (who defeated Republicans David Perdue and Kelly Loeffler in the Georgia special elections and their runoffs) not being inaugurated until January 20 (the same day which Joe Biden was inaugurated President), the Republicans held the Presidency and the Senate until Biden, Ossoff, and Warnock were all sworn in, at which time the Democratic Party obtained a trifecta.
  72. ^ In the 118th Congress, Angus King, Bernie Sanders, and Kyrsten Sinema continued to serve as Independent Democrats, and Democratic senator Joe Manchin switched to join them on May 31, 2024.
  73. ^ During the 118th Congress, George Santos (R-NY3) was expelled by a vote of 311 to 114 on the first of December, 2023.
  74. ^ The beginning of Lincoln's second term and of George W. Bush's first term began with a trifecta for the Republican Party but ended very shortly after beginning.
  75. ^ The beginning of William Harrison's term began as a trifecta for the Whigs. It continued after Harrison's death when Tyler became President, but ended shortly after once the Whig Party expelled Tyler into becoming an independent.
  76. ^ The Democrats and Republicans shared control of the Senate in the 47th United States Congress. In the middle of the 107th United States Congress, control of the Senate switched from the Republican Party to the Democratic Party.
  77. ^ During the 27th Congress, the Whigs expelled the sitting president, John Tyler, from their party. Tyler governed as an independent.
Quelle: https://en.wikipedia.org/wiki/Party_divisions_of_United_States_Congresses