Hamilton was born in Boonsboro, Maryland, and received early schooling from a local tutor named John Brown.

In 1874, Hamilton was abandoned by the state Democratic Party during the nomination process for his senate seat, and was not considered by them for re-election.

Instead, Hamilton ran for governor in 1875, but lost his party's nomination to fellow Democrat John Lee Carroll.

After failing to receive nomination for governor, Hamilton again stepped away from the political arena, returning to his previous engagements in Western Maryland.

Hamilton faced future U.S. Postmaster General, Republican James Albert Gary, during the election, and defeated him by more than 22,000 votes.

He was maintained a great deal of popularity in Hagerstown and the surrounding areas, and his death following a long battle with illness was widely mourned.