Marthasville was an early name for Atlanta, Georgia. Marthasville was named for Governor Wilson Lumpkin's daughter, Martha; it was officially incorporated on December 23, 1843. Prior to the name "Marthasville," the town was called Terminus (as in, end of the railroad).
Two years later, the name of the town was changed to Atlanta, by Act 109 of the Georgia General Assembly, which was approved December 26, 1845, and signed into law three days afterward. In the same act, the election precinct known as the Whitehall precinct (in the home of Charner Humphries) was also changed to Atlanta. In 1847, the city's charter was approved, elections were held; and the first slate of councilmen and the mayor took office in January 1848.
Note that Georgia's capital city at that time was Milledgeville. Atlanta was not designated the capital until after the Civil War.
AN ACT to change the name of Marthasville, in DeKalb county, to that of Atlanta; also, to change the election precinct now held at the house of Charner Humphries, known as the Whitehall precinct, to Atlanta.