All 230[Note 2] seats to the United States House of Representatives
116 seats were needed for a majority
The Whigs gained 37 seats to win 116 and a change in partisan control, while the rival Democrats lost 30, falling to 112.[Note 3] The Whigs gained seats in the Mid-Atlantic and the South. The nativist and anti-Catholic American Party was reduced to a single seat. One Independent, Amos Tuck, was elected from New Hampshire.
The Mexican–American War was the main issue. The incumbent House had voted for war by 174 to 14, but Polk had won the Presidency only by plurality in 1844 over his more famous opponent Henry Clay. War with Mexico was enthusiastically supported west of the Appalachian Mountains, but voters in northeastern, more urban regions widely opposed the war. Growing divisions over slavery factored, as Congressional rejection of the Wilmot Proviso aggravated sectional tensions.
Notable freshmen included Abraham Lincoln, elected as a Whig to his only term in Congress. This was the last time the Whigs ever held a majority in the House (though they would form part of the majority formed after the fractious 1854 election.
The trend toward single-member districts culminated as no multi-member districts featured.
In 1845, Congress established an uniform date for choosing Presidential electors. Gradually, states aligned nearly all other elections with this date, though as of this election, only three states had done so.
|Missouri||District[Note 4]||August 2, 1846||5||0||5||0|
|Arkansas||At-large||August 3, 1846||1||0||1||0|
|Illinois||District||August 3, 1846||7||1||6[Note 5]||0|
|Vermont||District||September 1, 1846||4||3||1||0|
|Maine||District||September 14, 1846||7||1||6||0|
|Florida||At-large||October 5, 1846||1||1||1||0||1||0|
|Georgia||District||October 5, 1846||8||4||1||4||1||0|
|South Carolina||District||October 12–13, 1846||7||0||7||0|
|Ohio||District||October 13, 1846||21||11||3||10||3||0|
|Pennsylvania||District||October 13, 1846||24||16||6||7||5||1[Note 6]||1|
|Texas||District||November 2, 1846||2||0||2||0|
|Michigan||District||November 3, 1846
|New York||District||34||23||14||11[Note 7]||10||0||4|
|Massachusetts||District||November 9, 1846||10||10||0||0|
|Delaware||At-large||November 10, 1846||1||1||0||0|
|New Hampshire||District[Note 4]||March 9, 1847||4[Note 8]||1||1||2||1||1[Note 9]||1|
|Connecticut||District||April 5, 1847||4||4||0||0|
|Rhode Island||District||April 7, 1847||2||1||1||1||1||0|
|Virginia||District||April 22, 1847||15||6||5||9||5||0|
|Alabama||District||August 2, 1847||7||2||1||5||1||0|
|Indiana||District||August 2, 1847||10||4||2||6||2||0|
|Iowa||District[Note 4]||August 2, 1847||2||0||2||0|
|Kentucky||District||August 2, 1847||10||6||1||4||1||0|
|Tennessee||District||August 2, 1847||11||5||6||0|
|North Carolina||District||August 5, 1847||9||6||3||3||3||0|
|Maryland||District||October 6, 1847||6||4||2||2||2||0|
|Mississippi||District[Note 4]||November 1–2, 1847||4||1||1||3||1||0|
|Louisiana||District||November 2, 1847||4||1||3||0|
|Wisconsin[Note 10]||District||May 8, 1848||2||0||2||2||0|
|Florida at-large||William H. Brockenbrough||Democratic||1845 (special)||Retired
|Edward C. Cabell (W) 50.9%|
William A. Kain (D) 49.1%
- United States elections, 1846
- 29th United States Congress
- 30th United States Congress
- Excludes states admitted during the 30th Congress.
- Includes late elections
- Includes 2 Independent Democrats elected to IL-01 and NY-17 – see: Martis, p. 100-101.
- Changed from at-large
- Includes Robert Smith, who was elected to IL-01 as an Independent Democrat.
- 1 American
- Includes George Petrie, who was elected to NY-17 as an Independent Democrat.
- One seat had been vacant during the entire 29th Congress.
- Amos Tuck was elected to NH-01 as an Independent.
- New state
- 9 Stat. 58
- Dubin, Michael J. (March 1, 1998). United States Congressional Elections, 1788-1997: The Official Results of the Elections of the 1st Through 105th Congresses. McFarland and Company. ISBN 978-0786402830.
- Martis, Kenneth C. (January 1, 1989). The Historical Atlas of Political Parties in the United States Congress, 1789-1989. Macmillan Publishing Company. ISBN 978-0029201701.
- Moore, John L., ed. (1994). Congressional Quarterly's Guide to U.S. Elections (Third ed.). Congressional Quarterly Inc. ISBN 978-0871879967.
- "Party Divisions of the House of Representatives* 1789–Present". Office of the Historian, House of United States House of Representatives. Retrieved January 21, 2015.
- Office of the Historian (Office of Art & Archives, Office of the Clerk, U.S. House of Representatives)