The 1846–47 United States House of Representatives elections were held on various dates in various states between August 2, 1846 and November 2, 1847. Each state set its own date for its elections to the House of Representatives. 228 elected members representing 29 states took their seats when the first session of the 30th United States Congress convened December 6, 1847. The new states of Iowa and Texas elected their first representatives during this election cycle. These elections were held during President James K. Polk's term.
The Whigs gained 37 seats to win 116 and a change in partisan control, while the rival Democrats lost 30, falling to 112. The Whigs gained seats in the Mid-Atlantic and the South. The nativist and anti-Catholic Native American Party, also known as the Know Nothings, was reduced to one seat. One Independent, Amos Tuck, was elected from New Hampshire.
The Mexican–American War, which the incumbent House had voted overwhelmingly to approve, was the main issue. The war had much stronger voter support in the West, South, and among Democrats than in the East, North, and among Whigs.
It was widely, accurately believed that war with Mexico would be won with large territorial gains. The Wilmot Proviso was the first congressional attempt to address slavery in these projected new territories, by proposing to ban it. Congress rejected the Wilmot Proviso, but not quickly or smoothly. Protracted debate aggravated sectional tensions. The repeated failure of Congress, and later also the President and Supreme Court, over the next decade to resolve the issue of slavery in the territories was a major cause of the Civil War.
This was the last time the Whig Party won a House majority, though candidates opposed to the Democratic Party would win a large majority in the realigning 1854 election. Notable freshmen included Abraham Lincoln of Illinois, elected as a Whig to his only term.
Election summaries
The trend toward single-member districts culminated as no multi-member districts featured.
In 1845, partly motivated by the successful 1844 test of the electric telegraph between Washington and Baltimore, Congress established a uniform date for choosing Presidential electors. Gradually, states aligned nearly all elections with this date, though as of this election, only three states had done so.
Two seats were added for the new State of Wisconsin. Wisconsin was unrepresented for most of the first session.
Special elections
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! | Washington Poe | | Democratic | 1844 | | Member-elect declined the seat.New member elected January 5, 1846.Democratic hold. | nowrap |
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! | Sterling Price | | Democratic | 1844 | | Incumbent resigned August 12, 1846 to serve in the Mexican–American War.New member elected October 31, 1846 and seated December 7, 1846.Democratic hold.Successor had not been elected to the next term; see below. | nowrap | |- ! rowspan=2| | colspan=3 rowspan=2| None (New state) | | Member-elect elected to the Senate.New member elected October 6, 1845. Whig gain. | nowrap rowspan=2| |- | | Recount places newly elected member in second place.Member removed from the seat, and the true victor is seated. Democratic gain. |-
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! | Archibald Yell | | Democratic | 18361840 1844 | | Incumbent resigned July 1, 1846 to serve in the United States Volunteers.New member elected December 14, 1846.Whig gain.Successor seated February 6, 1847.Successor had not been elected to the next term; see below. | nowrap |
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! | Edward D. Baker | | Whig | 1844 | | Incumbent resigned January 15, 1847 to join the Illinois Volunteer Infantry.New member elected January 20, 1847 to finish the term.Whig hold.Successor had not been a candidate to the next term; see below. | nowrap |
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! | Edward Bradley | | 1846 | | Incumbent died August 5, 1847.New member elected November 2, 1847.Democratic hold. | nowrap |
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Alabama
Elections were held August 2, 1847, after the March 4, 1847 beginning of the term, but before the House first convened in December 1847.
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Arkansas
Arkansas elected its sole member August 3, 1846.
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! | Archibald Yell | | Democratic | 18361840 1844 | | Incumbent resigned July 1, 1846 to serve in the United States Volunteers.New member elected.Democratic hold.Winner was not elected to finish the current term. | nowrap |