James Harlan was born in Clark County, Illinois, in 1820. He received his education at an Indiana county school and taught in a district school before attending Indiana Asbury University (now DePauw University), graduating in 1845. Later that year, he moved to Iowa City, Iowa, and by 1847 was serving as superintendent of public instruction.

Harlan also studied the law and was admitted to the bar in 1850, the same year he declined the Whig nomination to become governor of Iowa. From 1853 to 1855, Harlan served as president of Iowa Wesleyan College, before being elected to the United States Senate in 1855 as a Free Soiler. Because of irregularities associated with that election, he ran for the Senate yet again in 1857, this time as a Republican -- having joined the newly created party in 1856 -- and successfully defended his seat.

Harlan was reelected again in 1860 but did not serve out his full term, for in 1865 President Abraham Lincoln tapped him to become secretary of the interior following the resignation of John Palmer Usher. Although he had been confirmed, Harlan had not yet taken office when Lincoln was assassinated and therefore could not become secretary of the interior unless President Johnson renominated him. The new President did so, and Harlan assumed his post. However, after a year in office, Harlan resigned in protest over the administration's policies.

Harlan immediately reassumed his old Senate seat but failed to secure reelection in 1872, having been tainted with corruption -- charges that were never proven. Yet the cloud of corruption continued to follow Harlan, preventing yet another successful run for the Senate in 1875. Although renominated yet again in 1881, Harlan withdrew and served as the presiding judge of the Alabama Claims Commission from 1882 to 1886. James Harlan died in 1899.