Sumner was elected in 1851 by a single vote after twenty-five inconclusive ballots by a coalition of Free-Soil and Democratic legislators.

During the election, Sumner was still recovering from a brutal attack by a fellow member of Congress, Preston Brooks.

Brooks considered his attack retaliation for a Sumner's speech given two days earlier, in which Sumner fiercely criticized slaveholders including South Carolina Senator Andrew Butler, author of the Kansas-Nebraska Act and Brook's relative.

[3] In a noted contrast[1] from the divisive and lengthy 1851 election, Sumner was re-elected overwhelmingly by the House on January 9.

Some protest votes were cast for conservative former Whig politicians who had become independents or Democrats following the party's dissolution in 1856.