Election by the state legislature in with each chamber voting separately. Senator McMillan won 29 of 36 votes in the state Senate with five for Buck and one each for Severance and Davis. McMillan won 92 of 100 votes in the state House with four for Sibley and two for Roberts. The legislature declared McMillan the duly elected U.S. Senator in a joint convention on January 19, 1881.
Buck was an attorney from Mankato, Democratic nominee for Secretary of State in 1861, former state Representative (HD 17, 1866-1867), state Senator (SD 14, 1879-1883), Democratic nominee for Lieutenant Governor in 1888, and Minnesota Supreme Court Associate Justice (1893-1899).
Sibley was a Wisconsin U.S. House territorial delegate (1848-1849), Minnesota U.S. House territorial delegate (1849-1853), member of the Minnesota Territorial House (HD 06, 1855), member and president of the 1857 Minnesota Constitutional Convention, and first Governor of the state (1858-1860).
Roberts was a professor from Rochester and Greenback nominee for the 1st CD in 1880 and 1882.
Severance was an attorney and former state Republican legislator (HD 19, 1862-1863) but was backed by Democratic state Senator Daniel Buck. He was unaninmously nominated for the 6th Judicial District seat later in the year by the Democratic and Republican conventions.
Davis was an attorney from St. Paul, former state Representative (HD01, 1867-1868), U.S. Attorney (1868-1873), and Governor (1874-1876).