Center City was in Hamilton County until 1887. In fact, the Hamilton County line was seven miles south of Center City at Sims Creek. 

Thomas J. Proctor was the first postmaster of the Center City Post Office, Hamilton County, when he was appointed on 4 June, 1877. Others who were postmasters at Center City while it was part of Hamilton County were:

L. R. Sullivant - 15 March, 1881

Thomas S. Hawkins - 13 October, 1881