John Forster, the son of John Forster and Catharine Dickey, daughter of Moses Dickey, was born in Paxtang Township, Lancaster County (now Susquehanna Township, Dauphin County), Pennsylvania, on September 17, 1777. Received a subscription education; attended Princeton; but left school to serve in the 1794 Whiskey Rebellion. He subsequently read law with John Andre Hanna but never applied for admission to the local bar. Pursued a successful private business; appointed Captain in the state militia; and rose to rank of Colonel during the War of 1812 after distinguished service in Baltimore (1814). Elected to the state Senate, 1814-1818; cashier of the Harrisburg Bank for 16 years; established the Bank of Lewistown; and in 1840 was cashier of the Exchange Bank of Pittsburgh. He subsequently became president of the branch bank at Hollidaysburg, but in a few years retired from all business pursuits and returned to his home at Harrisburg. He died there on May 28, 1863, at 86. Forster married twice: Mary Elder, daughter of John Elder, and second; Margaret Snodgrass, daughter of Benjamin Law.
Location, portraitist, and ownership of portrait is unknown. Forster Street is named in his honor