William King was born in Scarborough on February 9, 1768 to Richard King and Mary Black King. William had very little formal schooling and was mainly a self-educated and self-made man. William served as major general during the War of 1812, leading to his interest in coastal shipping and defense in the District of Maine. He petitioned for statehood for Maine and realized this goal after seven long years, on March 15, 1820. He was elected the following month as Maine's first governor.

In 1800 he married Anne Frazier of Boston and relocated to Bath. William died in Bath at home on June 17, 1852.