Born in the neighborhood of Manayunk, in Philadelphia, Pennsylvania on July 19, 1909, Hamilton was one of the sons of William J. Hamilton Sr. and a member of a prominent Republican family in the city.

[1] He served in the United States Army during World War II.

After receiving training at the American Institute of Banking, he worked in the mortgage and bond business.

He rose through the ranks of the Republican Party hierarchy to become Chairman of the City Committee, the effective boss of the organization.

[1] On the way home from the 1965 Republican National Convention, Hamilton suffered a heart attack and died suddenly at the age of 55.