Decatur is a city in, and county seat of, DeKalb County, Georgia, United States.With a population of 20,148 in the 2013 census, the city is sometimes assumed to be larger since multiple zip codes in unincorporated DeKalb County bear the Decatur name.
In 1822 Decatur was founded at the intersection of two Native American trails: the Sandtown which led east from the Chattahoochee River at Utoy Creek, and the Shallowford which follows today's Clairmont Road and eventually crossed near Roswell. During the American Civil War, Decatur became a strategic site in Sherman's campaign against Atlanta. In July 1864 Union general James B. McPherson occupied Decatur to cut off the Confederates' supply line from Augusta, Georgia. During the Battle of Atlanta on July 22, Confederate cavalry under Major General Joseph Wheeler attacked McPherson's supply wagons and the Union troops left to defend the wagons. A marker at the Decatur courthouse marks the site of this skirmish.