1854–55 United States House of Representatives elections

← 1852 & 1853 August 4, 1854 – November 6, 1855 1856 & 1857 →
All 234 seats in the United States House of Representatives[1] 118 seats needed for a majority
First party Second party Third party   Leader William A. Richardson Henry M. Fuller Nathaniel P. Banks Party Democratic Whig Know Nothing Leader's seat Illinois 5th Pennsylvania 12th Massachusetts 7th Last election 150 seats 68 seats 0 seats Seats won 83[a][2][3] 54[c] 51[2][3][d] Seat change 69 14 51 Popular vote 1,418,553[b] 580,929 631,510 Percentage 43.95% 18.00% 19.56% Swing 5.87% 23.61% 19.25%   Fourth party Fifth party Sixth party   Party Anti-Nebraska Republican People's Last election Pre-creation Pre-creation Pre-creation Seats won 22[c] 13[c] 9[4][c] Seat change 22 13 9 Popular vote 196,461 182,245 102,423 Percentage 6.09% 5.65% 3.17% Swing New Party New Party New Party   Seventh party Eighth party   Party Free Soil Independent Last election 4 seats 3 seats Seats won 1[c] 1[e] Seat change 3 2 Popular vote 22,928 84,196[f] Percentage 0.71% 2.61% Swing 3.28% 0.18%
Results:      Democratic gain      Whig gain      Democratic hold      Whig hold      American gain      Anti-Nebraska gain      Republican gain      People's gain      Independent gain
Speaker before election Linn Boyd Democratic Elected Speaker Nathaniel P. Banks Know Nothing/American

The 1854–55 United States House of Representatives elections were held in 31 states for all 234 seats between August 4, 1854, and November 6, 1855, during President Franklin Pierce's term. Each state legislature separately set a date to elect representatives to the House of Representatives before the 34th Congress convened its first session on December 3, 1855.

This midterm election was among the most disruptive in American history, auguring the collapse of the Second Party System. Both major parties, the Democratic Party and the Whig Party, organized as rivals for roughly 20 years, lost critical voter support. Northern voters strongly opposed to the Kansas–Nebraska Act shifted sharply against Democrats. Whigs also lost seats as the party disintegrated over slavery.

The elected majority temporarily coalesced as the Opposition Party. This transitional party included Whigs, Free Soil members, American Party members or Know Nothings, the People's Party of Indiana, Anti-Nebraska candidates, disaffected Northern Democrats, and members of the nascent Republican Party, which soon would absorb most of these factions and replace the Whigs to rival the Democrats.

Candidates opposed to the Democratic Party won widely in the North through November 1854. The American Party, ignoring slavery and opposing immigration (particularly by Catholics from Ireland and Germany) won seats from both major parties, but to the net loss of Democrats, in New England and the South from November 1854 into 1855.

Congress had passed the Kansas–Nebraska Act in May 1854 after aggressive sponsorship by the Pierce Administration and Democrats led by Senator Stephen Douglas, including radical pro-slavery legislators. The Act repealed the 1820 Missouri Compromise and triggered the Bleeding Kansas conflict. With widely foreseen risks and immediately negative results, the act publicly discredited the Democratic Party, fueling new partisan and sectional rancor. It created violent uncertainty on the frontier by abruptly making slavery potentially legal in territories originally comprising the northern portion of the Louisiana Purchase and attractive to contemporary settlers. Settlers were expected to determine the status of slavery locally. This idea appealed to Democratic politicians and to some voters, but proved unworkable in Kansas where the status of slavery would be violently disputed between more numerous Northern settlers and geographically closer Southern settlers. Even some pro-slavery legislators and voters, particularly Southern Whigs, felt repealing the Missouri Compromise was politically reckless and attempting to push slavery by law and force into territories where most settlers predictably were unlikely to want it endangered slavery everywhere, even in the South. These fears proved prescient.

More than 21 representatives vied for the post of speaker of the House. After two months and 133 ballots, American Party representative Nathaniel Banks of Massachusetts, also a Free Soiler, defeated Democrat William Aiken of South Carolina by plurality, 103–100.^[5] To date, Banks is the only speaker to come from a third party.

Election summaries