Milton County was named for John Milton, Georgia's first secretary of State. He was credited with saving the official records of Georgia when the British occupied the state. Some of his descendants were General Homer V. Milton of the 1812 war, Governor John Milton of the state of Florida, General William H. Milton of the Confederate Army, and Mrs. William Y. Atkinson, wife of the Governor Of Georgia. Thanks to W.S. Bates, Milton County Historian, Old Milton County History and Genealogy Group, for this information.
Milton County was formed in 1857 from parts of Cherokee, Forsyth and Cobb Counties. Portions of DeKalb and Gwinnett counties were annexed in 1859. The county seat was Alpharetta. Milton County was a very poor county. There was only one paved road and no school buses. Fulton County wanted to expand and promised Milton County paved roads, school buses and a better school if they agreed to a merger. Roswell, which was never a part of Milton County, was also approached. In 1932 Milton County, along with the city of Roswell, became part of Fulton County.
Thanks to http://www.mindspring.com/~ednab/