Covering 280 square miles in southwest Georgia, Calhoun County was created from parts of Early and Baker counties in 1854. The county is named for John C. Calhoun, the U.S. vice president under presidents John Quincy Adams and Andrew Jackson. It has four incorporated cities: Arlington, Edison, Leary, and Morgan.
Morgan, the county seat, was incorporated in 1856. Although Morgan, named for either Hiram Morgan, one of the town's first commissioners, or Daniel Morgan, a general during the Revolutionary War (1775-83), was not the largest city in the new county, it was named the county seat after a unique proposal was used to determine the site. According to local history, one political faction wanted the county seat to be in Concord, a small community north of present-day Leary, and a second faction wanted it to be in Whitney, later named Dickey. The leader of each faction agreed to "split the difference" by establishing the seat halfway between Concord and Whitney. They measured the distance by tying a rag to the wheel of a buggy and counting the rotations made by the wheel between the two towns. Both men rode in the buggy and counted the revolutions. After arriving in Whitney, they turned the buggy around and traveled the same road back until the wheel had made exactly half the number of revolutions. It was there that the two leaders set a stake to mark the site of the courthouse in the county seat, which was eventually named Morgan.
The Colonial Revival–style courthouse was rebuilt in 1935 and renovated in 1972, after two previous structures were destroyed by fire in 1888 and 1920. In 1923, following a county referendum, the state legislature moved the county seat to Arlington. Six years later, however, voters petitioned for it to be returned to Morgan, and in 1929 Morgan again became the county seat. Calhoun County Middle/High School and a public library are located in Edison. Designated a "Better Hometown City," Edison has been beautified with brick sidewalks, cast-iron handrails, and period lighting, and the city's commercial district was added to the National Register of Historic Places in 2000. Also on the register is the Arlington United Methodist Church in Arlington, which was listed in 1990.
More than 50 percent of the land in the county has been designated as prime farmland by the U.S. Department of Agriculture. The main crops are corn, oats, sorghum, and wheat. In recent years the number of family-owned farms has declined, and Calhoun County, home to several endangered plant and animal species, including the swamp buckhorn, yellow flytrap, and the gopher tortoise, now has many wildlife plantations.
The annual May Day festival in Arlington, held the first Saturday in May, is one of the oldest festivals in Georgia. Other events include the King Cotton Horse Show, held in Edison each May, and the Harvest Festival, held on the courthouse square in Morgan every November.
According to the 2010 U.S. census, the population of Calhoun County is 6,694, an increase from the 2000 population of 6,320.