1856–57 United States Senate elections

← 1854 & 1855 Various dates 1858 & 1859 →
21 of the 62 seats in the United States Senate (with special elections) 32 seats needed for a majority
Majority party Minority party Third party   Party Democratic Republican Whig Last election 33 seats 3 seats 20 seats Seats before 37 11 8 Seats won 9 10 0 Seats after 34 18 3 Seat change 3 7 5 Seats up 12 3 5   Fourth party Fifth party   Party Know Nothing Free Soil Last election 1 seat 2 seats Seats before 1 2 Seats won 1 0 Seats after 2 1 Seat change 1 1 Seats up 0 1
Results of the elections:      Democratic gain      Democratic hold      Republican gain      Republican hold      Know Nothing Gain      Legislature failed to elect
Majority Party before election Democratic Elected Majority Party Democratic

The 1856–57 United States Senate elections were held on various dates in various states. As these U.S. Senate elections were prior to the ratification of the Seventeenth Amendment in 1913, senators were chosen by state legislatures. Senators were elected over a wide range of time throughout 1856 and 1857, and a seat may have been filled months late or remained vacant due to legislative deadlock.^[1] In these elections, terms were up for the senators in Class 1.

The young Republican Party assumed its position as one of the United States's two main political parties. The Whigs and Free Soilers were gone by the time the next Congress began.

Results summary

Senate party division, 35th Congress (1857–1859)

• Majority party: Democratic (37–42)
• Minority party: Republican (20)
• Other party: American (4)
• Vacant: 1–0
• Total seats: 62–66

Change in composition

Before the elections

After the January 14, 1856 special election in Pennsylvania.

As a result of the elections

Beginning of the next Congress