Colfax entered politics at the age of 21, delivering campaign speeches for the Whig presidential candidate, Henry Clay, in 1844. He was a delegate to Whig national conventions in 1848 and 1852, but was defeated as a Whig candidate for Congress in 1851. During the political upheaval of the early 1850s Colfax joined the new Republican party and was elected to Congress as a Republican in 1854. As chair of the House Committee on Post Offices and Post Roads, he oversaw the reorganization and expansion of the transcontinental mail service. In 1861 he was a leading contender for the cabinet position of postmaster-general in the Lincoln administration, but Montgomery Blair from the crucial border state of Missouri was selected instead. In all, Colfax was reelected to seven consecutive terms in the House and served as Speaker from 1863 until assuming the vice presidency in March 1869.

In 1868 the Republican party selected him as Ulysses S. Grant's vice-presidential running-mate. In 1872, however, Colfax alienated Grant and his supporters by hinting that he might stand for the presidency if Grant decided not to seek a second term. As a result, the Republican National Convention replaced Colfax with Senator Henry Wilson of Massachusetts. Shortly thereafter, Colfax was accused of accepting, while he was Speaker of the House, cut-rate stock in the Crédit Mobilier in return for not investigating allegations of corruption in the construction of the Union Pacific Railroad. Although he escaped censure and claimed to have been exonerated, his political career was destroyed. Upon the end of his term as vice president, Colfax became a popular speaker on the lecture circuit. After arriving for a lecture in Mankato, Minnesota, on January 13, 1885, he died of a heart attack after stepping outside into the minus-30 degree temperature.

Sources consulted: Dictionary of American Biography; William A. DeGregorio, The Complete Book of U. S. Presidents; Harper's Encyclopedia of United States History.