1848 United States elections

The 1848 United States elections elected the members of the 31st United States Congress. The election took place during the Second Party System, nine months after the Treaty of Guadalupe Hidalgo ended the Mexican–American War. With the issue of slavery (and its extension into western territories) dividing the nation, the Free Soil Party established itself as the third most powerful party in Congress. California joined the union before the next election, and elected its first Congressional delegation to the 31st Congress. Whigs won the Presidency, but Democrats won a plurality in the House and retained control of the Senate.

1848 United States elections

Presidential election year
Election day	November 7
Incumbent president	James K. Polk (Democratic)
Next Congress	31st
Presidential election
Partisan control	Whig gain
Popular vote margin	Whig +4.8%
Electoral vote
Zachary Taylor (W)	163
Lewis Cass (D)	127
1848 presidential election results. Blue denotes states won by Cass, buff denotes states won by Taylor. Numbers indicate the electoral votes won by each candidate.
Senate elections
Overall control	Democratic hold
Seats contested	19 of 60 seats[1]
Net seat change	Whig +4[2]
House elections
Overall control	Democratic gain[3]
Seats contested	All 237 voting members
Net seat change	Democratic +1[2]

In the Presidential election, Whig General Zachary Taylor defeated Democratic former Senator Lewis Cass of Michigan and the Free Soil candidate, former President Martin Van Buren.[4] Taylor won most of the Northeast and several Southern states, giving him a fairly comfortable majority in both the electoral and popular vote. One-term incumbent Democratic President James K. Polk chose to retire rather than seek re-election (becoming the first elected president to do so), and Cass defeated Supreme Court Justice Levi Woodbury and Secretary of State James Buchanan on the fourth ballot at the 1848 Democratic National Convention. Van Buren, the former Democratic President, ran against Cass for political reasons (Cass was a prominent supporter of slavery) and possibly for personal reasons (Cass helped defeat Van Buren's 1844 bid for the Democratic nomination).[5] Taylor was recruited by the Whigs to replicate the success of the Whig's only previous successful candidate, General William Henry Harrison, and he easily triumphed over other Whig candidates. Taylor's win made him the last President to win election as neither a Democrat nor a Republican.

In the House, Democrats picked up a small number of seats, taking the plurality. The Whigs lost a small number of seats but remained the second largest party, while the Free Soil Party picked up a handful of seats.[6] The House elected Democrat Howell Cobb as Speaker after sixty-three ballots.[7]

In the Senate, the Whigs won minor gains, cutting into the Democratic majority.[8]

This was the first time the presidency and one house of Congress flipped control to different parties. In this instance, the Whig Party flipped the presidency but lost control of the House of Representatives. This would not happen again until 2000 where the Republican Party flipped the presidency but lost control of the senate.