The Milton name predates the modern city by more than a century. The original Milton County, Georgia was established in 1857 and named for John Milton, the Revolutionary War-era Secretary of State of Georgia. That county operated for roughly seventy-five years until the Great Depression pushed it into financial distress, at which point the Georgia General Assembly merged it into Fulton County in 1932. For the next seven decades the area was administered as unincorporated north Fulton.
Residents in the area voted in 2006 to re-incorporate as a new city, and the City of Milton was formally established on December 1, 2006. The incorporation was a deliberate response to development pressure: residents wanted local control over zoning so the rural character, horse farms, and large-lot estate housing would not be displaced by dense subdivision development radiating up from Alpharetta and the GA-400 corridor.
One of the new city government's first actions was to lock in AG-1 (Agricultural) as the default base zoning across most of its land area, requiring a one-acre minimum lot size for new residential construction. The same period preserved the Crabapple village node along Crabapple Road, the Birmingham Crossroads commercial cluster, and the network of equestrian farms that distinguish Milton from denser parts of north Fulton.