 William J Green III who was elected in 1979, was the last.Clark was inaugurated as the 90th Mayor of Philadelphia on January 7, 1952.He was the first mayor to serve under Philadelphia's Home Rule Charter, which had reorganized city government by merging Philadelphia's city and county offices, establishing a limit of two successive terms for mayor, replacing patronage with a merit system for civil servants, and giving the mayor increased administrative, legislative, and investigative powers.