Henry County is a growing suburban county located in the U.S. state of Georgia. As of the 2000 census, the population was 119,341. As of the 2010 census, the county's population swelled to 203,922, up 70.9% from the previous census and becoming Georgia's 8th most populous county and the 10th fastest growing county in the nation. The county seat is McDonough. This county is a part of the Atlanta Metropolitan Area.
Henry County, Georgia was created by the Georgia State Legislature in 1821 from land acquired from the Creek Indian Nation by the First Treaty of Indian Springs. Henry's original land area was much larger than it is today, stretching from near Indian Springs (present-day Indian Springs State Park) in the south to the Chattahoochee River near Sandy Springs in the north; encompassing most of present day Metropolitan Atlanta. Before one year passed the size of the County was diminished through the separation of land areas which, in whole or in part, became present day DeKalb, Fulton, Fayette and Newton Counties. Later divisions resulted in Clayton, Spalding, Rockdale and Butts Counties.
In the beginning Henry County was a virgin wilderness, having just been ceded from the Creek Nation. Prior to 1821, the Creeks and a few trappers and traders were the only residents of this area. The Creek Indians left their mark through place names, a few small Indian Mounds scattered around the County and through the arrowheads and broken pottery which can be found throughout Henry County.
Jesse Johnson, son of John Johnson and great-grandfather of U.S. President Lyndon Baines Johnson, was a "first settler" of Henry County. He was a prosperous farmer, sheriff (1822–1835), and judge, before he emigrated to Alabama.