William Freame Johnston

William F. Johnston was born on November 29, 1808 in Greensburg, Pennsylvania. His parents were Alexander Johnston, an Ulster Scots immigrant from County Tyrone and Elizabeth (Freame) Johnston. In 1832, Johnston married Mary Ann Montieth (1814–1898). The couple had five sons and two daughters.

Johnston was a lawyer by training, becoming the district attorney of Westmoreland County at the age of 21 in 1829. He was elected to the Pennsylvania state legislature and in 1847 ran for the Pennsylvania Senate. Jonston was named Senate Speaker in 1848 and upon the resignation of Governor Francis Shunk, assumed the position of governor.