Following his admission to the bar, Calhoun practiced law in Decatur. During the
Creek War of 1836, he was a captain and commanded a cavalry company at Fort McCrary. Politically, Calhoun was a
Whig in a largely Democratic district but was still elected to the
Georgia General Assembly in 1837 from
DeKalb County. From 1840 to 1850, he practiced law with his brother-in-law William Harris Dabney in DeKalb County. He also practiced law with B. F. Martin, A. W. Stone, and his son
William Lowndes Calhoun. He also owned farms. He served in the
Georgia State Senate in 1851. In 1852, Calhoun moved to
Atlanta. He served in the Georgia State Senate, representing
Fulton County from 1855 to 1856. He was a member of the judiciary committee. He was vice president of the
1860 Constitutional Union Convention.
Mayor of Atlanta Calhoun served four one-year terms as its mayor from 1862 to 1865. In 1863, he commissioned a volunteer
militia to defend his city. When
Union troops under the command of William T. Sherman drew near during the
Atlanta campaign, much of the population of Atlanta, including Calhoun's wife and children, fled the city. This reduced the
population of Atlanta from around 22,000 to less than 3,000 when the
Confederate Army of Tennessee retreated from the city on September 1, 1864. Calhoun surrendered the city to Union forces under Sherman on September 2, 1864, writing, "Sir: The fortune of war has placed Atlanta in your hands. As mayor of the city I ask protection of non-combatants and private property." A marker now stands at the corner of
Peachtree Street and Alabama Street indicating where the surrender took place. Sherman replied by ordering the evacuation of the remaining civilian population of Atlanta on September 7, 1864. Calhoun and the city council protested this order, claiming that most of those who had not fled could not leave on account of their age, sickness, pregnancy, or destitution. In response, Sherman wrote back, accusing the Confederates of hypocrisy for invading Union territory and inflicting pains on American citizens, but only complaining when the reverse was done to them: Union soldiers under Sherman occupied the city for two months and burned much of it on November 15, 1864, in preparation for the
March to the Sea. ==Personal life==