Henry County was formed by the Georgia state legislature in 1821 from land acquired by the Creek Indians. The initial size of the county was much larger than it is today, as the county stretched from Indian Springs in the south to the Chattahoochee River near Sandy Springs in the North. Separations from this land in the following years created DeKalb, Fulton, Fayette, Newton Counties Clayton, Spalding, Rockdale and Butts Counties.
Henry County has experienced multiple periods of population growth over the years that have been followed by population declines. The periods of growth coincide with booms in the areas agriculture and transportation. Connections to major railroad lines in the 1840s and 1880s aided the growth of the Griffin and McDonough, the county seat. The destruction brought on by General Sherman’s “March to the Sea” in 1865 and the obliteration of the cotton crop due the cotton boll weevil in 1920 devastated the economy of Henry Country and caused tremendous population dips. Road construction, new schools, electricity, telephones, modern conveniences, new homes and businesses construction around the Atlanta metro-area in beginning in the 1940’s led to a decreased dependency on agriculture in Henry County and touched off a period of growth that continues today.