Atlanta is the fifth city to be designated capital of Georgia.
Several other cities have also served as temporary seats of government:

HISTORY OF GEORGIA CAPITALS

1777-78 Savannah
1779-80 Augusta*
1780-81 Heard's Fort*, miscellaneous sites in Wilkes County
1781-82 Augusta
1782 Ebenezer*, Savannah
1783 Augusta
1784 Savannah, Augusta
1785 Savannah
1786-96 Augusta
1796-1806 Louisville
1807-1864 Milledgeville
1864-65 Macon*
1865-68 Milledgeville
1868-present Atlanta