On December 21, 1836, the Georgia General Assembly voted to build the Western and Atlantic Railroad to provide a trade route to the Midwestern United States. Following the forced removal of the Cherokee Nation between 1838 and 1839 the newly depopulated area was opened for the construction of a railroad. The area around the eastern terminus to the line began to develop first. By 1842, the settlement had six buildings and 30 residents and the town was renamed "Marthasville". After a few renames, the Chief Engineer of the Georgia Railroad, J. Edgar Thomson, suggested that the area be renamed "Atlantica-Pacifica", which was quickly shortened to "Atlanta".The residents approved, and the town was incorporated as Atlanta on December 29, 1847.

The region where Atlanta and its suburbs were built was originally Creek and Cherokee Native American territory. In 1813, the Creeks, who had been recruited by the British to assist them in the War of 1812, attacked and burned Fort Mims in southwestern Alabama. The conflict broadened and became known as the Creek War. In response, the United States built a string of forts along the Ocmulgee and Chattahoochee Rivers, including Fort Daniel on top of Hog Mountain in present-day Norcross, Georgia, and Fort Gilmer. Fort Gilmer was situated next to an important Indian site called "Peachtree Standing", named after a large tree which is believed to have been a pine tree (the name referred to the pitch or sap that flowed from it). The word "pitch" was misunderstood for "peach", thus the site's name. The site traditionally marked a Native American meeting place at the boundary between Creek and Cherokee lands, at the point where Peachtree Creek flows into the Chattahoochee. The fort was soon renamed Fort Peachtree.