The act creating the county left naming it to the citizens, so no legal record exists telling the derivation of the name. For this reason, after The Civil War it became popular to attribute the name to commercial steamship inventor Robert Fulton. Records from the Atlanta Board of Trade (now, Chamber of Commerce) indicate the county is named for Hamiton Fulton, the state engineer that made the first survey of the Cherokee Nation between Chattanooga and present-day Atlanta. Stephen Long, who began building the Western and Atlantic Railroad in 1837, used much of Fulton's observations to plan a general route for the original railbed.
Fulton County was formed on December_20, 1853. By this time the new county seat, Atlanta, the thriving southern end of the Western and Atlantic Railroad of was larger than Decatur, county seat of DeKalb County, from which Fulton was taken.