William Johnson came from humble but proud stock in South Carolina. His father was a blacksmith and revolutionary patriot who was detained during the war for independence.
Johnson was educated at Princeton where he graduated first in his class. Upon graduation, Johnson returned to South Carolina where he read law and entered the bar.
Johnson served as a Republican in the South Carolina House of Representatives. Later he was chosen by the legislature to serve on the state's highest court.
Jefferson selected Johnson as his first of three Supreme Court appointments. Johnson will best be known for his independence in resisting the iron grip of Chief Justice John Marshall with whom he served for virtually all his years on the High Court. Johnson was the Court's first great dissenter.