Established December 20th, 1853, the name of Fulton County is commonly attributed to honor Robert Fulton, an inventor who experimented with a submarine boat in France (1801) and built the Clermont, a steamboat which sailed up the Hudson River in 1807. Recent research, however, tends to indicate that the county was actually named for an early railroad official, Hamilton Fulton, who acted as surveyor for the Western and Atlantic Railroad.
Campbell and Milton County merged with Fulton on January 1, 1932. Thirty years before Stephen Long placed a stake at the 0 mile post of the Western and Atlantic Railway in the area that today is known as Underground, whites moved into north Fulton County in the area known as Crabapple. The small group of buildings is the oldest town in the area, predating Roswell by some 20 years and Alpharetta by quite a few more. Birmingham, another small town north of Crabapple was also founded about the same time. About 20 years after the first settlers moved into Crabapple, a man name Roswell King was traveling in the area and purchased a few large tracts of land. He knew that the abundant waterpower on Vickery Creek was the perfect place to build a cotton mill. This mill would survive various fires, war and weather to produce fabric until the 1970's.
The area, then technically part of the town of Whitehall, would first become "Marthasville," then Atlanta in 1845.

In 1857 portions of Cherokee, Cobb and Gwinnett County were merged to create Milton County. The tiny town of New Prospect was chosen as county seat because of its central location. Before the county was formed, the city was renamed to Alpharetta, a combination of the Greek words for first and city.
North Fulton County housed a significant number of Union soldiers when General William Tecumseh Sherman arrived in here toward the end of the Atlanta Campaign. Men under the command of General Kenner Garrard destroyed Roswell Mill and sent the 400 women mill workers north to Indiana shortly after their arrival in July, 1864. The women and female children may have been assaulted by the Union soldiers near the mill on the morning of July 10, 1864, before their transport to Marietta later in the day.
General Hugh Kirkpatrick, Sherman's "Merchant of Terror" set the entire town of Atlanta on fire shortly before leaving on "The March to the Sea" in November, 1864.
After the Civil War, Milton County depended on the rebuilt Roswell Mills as a major industry, and grew cotton. It was bypassed by the railroads because of the mountains further north.
In Fulton County, Atlanta grew to become the Gateway City of the South. In 1913 the nation's eyes were riveted on Atlanta during the murder of young Mary Phagan and the prosecution of the man whom alledgedly killed her, Leo Frank During the Great Depression the counties of Milton and Campbell merged with Fulton, in part to save the expense of running a county government. Land from Cherokee, Cobb, and Gwinnett was incorporated into the deal to create a connected county.
growth continued. In 1977, President Jimmy Carter created the Chattahoochee National Recreation Area along the river that creates some of the county's borders.