| Election Name: | 1855 United States Senate special election in Massachusetts |
| Type: | presidential |
| Country: | Massachusetts |
| Ongoing: | no |
| Previous Election: | 1853 United States Senate election in Massachusetts |
| Previous Year: | 1853 |
| Next Election: | 1859 United States Senate election in Massachusetts |
| Next Year: | 1859 |
| Election Date: | January 23 and 31, 1855 |
| Votes For Election: | 40 members of the Massachusetts Senate 396 members of the Massachusetts House Majority vote of both houses needed to win |
| 1Blank: | Senate |
| 2Blank: | Percentage |
| 3Blank: | House |
| 4Blank: | Percentage |
| Image1: | Colonel Henry Wilson (Massachusetts Senator, U.S. Vice President).jpg |
| Nominee1: | Henry Wilson |
| Party1: | Know Nothing |
| 1Data1: | 21 |
| 2Data1: | 52.5% |
| 3Data1: | 234 |
| 4Data1: | 57.8% |
| U.S. senator | |
| Before Election: | Julius Rockwell |
| Before Party: | Whig Party (United States) |
| After Election: | Henry Wilson |
| After Party: | Know Nothing |
The 1855 United States Senate special election in Massachusetts was held during January 1855. Henry Wilson was elected to fill the remainder of the term left vacant by the resignation of Edward Everett.
Everett had resigned in 1854 over poor health and protest following his failure to vote against the Kansas-Nebraska Act. Prior to the election, Julius Rockwell had been appointed to the seat on an interim basis.
At the time, Massachusetts elected United States senators by a majority vote of each separate house of the Massachusetts General Court, the House and the Senate.
In 1854, the anti-immigration, anti-slavery American Party (better known as Know-Nothings) swept the Massachusetts elections, taking nearly every seat in the legislature.
Henry Wilson was nominated as the American Party candidate in a legislative caucus on January 13. Most of the House participated; none of the Senators did.[1] [2]
Following Wilson's endorsement by the caucus, public opposition was aroused against his election. On January 15, a printed circular called for a caucus of "all members in the House who believe in the freedom of debate, who refuse to sanction a high-handed course of political action, and who are opposed to the election of Hon. Henry Wilson to the United States Senate." The opposition caucus met and endorsed Alexander Bullock for Senator.[3]
Much of the debate in the House surrounded Wilson's loyalty to the American Party, or his lack thereof.[1] Wilson had been the Free Soil Party candidate for governor in 1854 but aligned himself with the nativist Know Nothing movement after their sweeping victory, in an effort to strengthen the party's emphasis on opposition to slavery. (The Free Soil Party had been dissolved into the new Republican Party.)
On January 23, the House convened and elected Wilson on the first ballot. His candidacy was then sent to the Senate for ratification.
On January 31, the State Senate convened and ratified the House's choice of Wilson.
Wilson joined Samuel Hoar's new anti-slavery Republican Party upon entering the Senate.