Who Has Controlled Congress? Every House and Senate Majority, 1900-2026

Which party has really run Congress? Watch every House and Senate majority from the 57th Congress (1901) to today's 119th, seat by seat, with every change of control: the 1910 and 1918 midterms, the deaths that flipped the House in 1931, the New Deal majorities, 1946, the 40-year House that began in 1955, 1980, 1994, the 50-50 Senates of 2001 and 2021, the senator whose switch flipped the Senate mid-session, and every midterm since. Data as of Oct 16, 2026. The Nov 3, 2026 midterm elections decide the 120th Congress (2027-2029); this video does not predict them. Chapters 0:00 1901: The 57th Congress opens 0:45 1910s: 435 seats and direct Senate elections 1:29 1919: Republican Congresses return 2:12 1931: Depression, New Deal and war 3:14 1947: Back and forth 3:43 1955: The 40-year House 5:21 1981: Split control 6:11 1995: The House flips after 40 years 6:34 2001: The 50-50 Senate 7:06 2007: Swing elections 7:55 2019: Narrow margins 8:35 What's next, and your call Which election do you think was the biggest turning point? Tell us in the comments. About the data House seats: U.S. House of Representatives, Office of the Historian, "Party Divisions of the House of Representatives, 1789 to Present" (history.house.gov/Institution/Party-Divisions/Party-Divisions/). These are the divisions from the initial election results for each Congress. Senate seats: U.S. Senate Historical Office, "Party Division" (senate.gov/history/partydiv.htm), the division immediately after each election, plus its notes on control changes during the 107th (2001-2003) and 117th (2021) Congresses. Current seats (Oct 16, 2026): Office of the Clerk, clerk.house.gov (218 Republicans, 214 Democrats, 1 independent, 2 vacancies) and senate.gov/senators (53 Republicans, 45 Democrats, 2 independents). Cross-check: Brookings Institution, Vital Statistics on Congress, Table 1-20 (first-day counts). Brookings is the source for the 118th Senate's opening count (48 D, 49 R, 3 independents); senate.gov lists 47-49-4, which reflects Sen. Manchin's May 2024 switch. Majority control: the party that organized each chamber. Vice-presidential tie-breaks decide the 50-50 Senates (2001, 2021-23) and the 1953 Senate. In 1917 (65th Congress) Democrats organized the House with third-party support despite winning fewer seats, and in 1931 (72nd) Democrats organized it after special elections, both per the House Historian. Method and caveats Seat counts are taken at the start of each Congress (from election results). Changes during a Congress (deaths, resignations, special elections, party switches) are NOT tracked, except notable cases: the 2001 Senate (Gore and Cheney tie-breaks, the Jeffords switch in June 2001, a Missouri special election in Nov 2002), the Georgia runoffs in Jan 2021, the Manchin switch in May 2024, and the House's current count as of Oct 16, 2026. "Other" means third parties and independents (Populists, Progressives, Farmer-Labor, Socialists, American Labor and others). Independents who caucus with a party are shown in a lighter shade next to it, only where the official source says so (Sen. Wayne Morse in 1955, Senate independents since 1971, and Rep. Kevin Kiley, who left the Republican Party in March 2026 and still caucuses with Republicans). The majority line is half the seats plus one, so it moves with chamber size: House 357 seats in 1901, 386 from 1903, 391 from 1907, 394 from 1911, 435 from 1913 (436-437 in 1959-63 after Alaska and Hawaii); Senate 90, 92, 96, then 100 from 1959. Years in control are counted from March 4, 1901 to Oct 16, 2026: House Democrats 75.8 years, Republicans 49.8; Senate Democrats 71.3, Republicans 54.3. Control changed hands 12 times in the House and 18 times in the Senate (four of those in 2001-2002). Counting rules from other sources can differ by a few weeks or seats. Streaks in the video start counting in March 1901, even when a party already held a chamber before then. Colors follow the U.S. convention (blue Democrats, red Republicans); both parties get the same treatment, sizes and sounds. Thumbnail photo: "Capitol Dome at Twilight," Architect of the Capitol, public domain (via Wikimedia Commons). No other photos are used. Music and sound are original, made for this channel. #congress #midterms #election2026 #history #dataisbeautiful #barchartrace Thumbnail gavel photo: Santeri Viinamäki (CC BY-SA 4.0), via Wikimedia Commons.