b. October 14, 1808, in Boston, Massachusetts; d. October 25, 1859, in St. Joseph, Missouri. Calhoun studied law at Fort Plain in Montgomery County, Illinois. In 1830, he came to Springfield, Illinois, and resumed the study of law, sustaining himself by teaching school. After serving in the Black Hawk War, the governor appointed Calhoun surveyor of Sangamon County. Calhoun convinced Abraham Lincoln to study surveying and to become his deputy. They continued as friends, although they were active in opposing political parties. Calhoun entered politics in 1835 and in 1838 was elected as state representative, his first state office. In 1848, Calhoun was appointed as one of three trustees of the state government to settle the outstanding affairs of the State Bank of Illinois after its liquidation. He served as mayor of Springfield from 1849 to 1850. In 1854, he moved to Kansas, where he became the Surveyor General of Kansas and Nebraska.