Newnan was incorporated and made the county seat of Coweta County on December 26, 1823. The city was named for General Daniel Newnan, who fought in the Indian Wars, the War of 1812, and later served in the Georgia General Assembly.

There are a number of antebellum homes in Newnan. Two popular historic sites include the Catalpa Plantation and the Oak Grove Plantation and Gardens, both built in 1835 and in the federal vernacular style home.