He was born on his family's farm near North East, Maryland, attended the Philadelphia Academy at New London and studied law. He was admitted to the Philadelphia Bar in 1753, and established a practice at New Castle, Delaware in 1754. He joined the Delaware Committee of Correspondence. He was appointed Attorney General to three Delaware counties, and was elected to the first Continental Congress in 1774. He voted against Lee's Resolution for Independence but joined with the majority in seeking independence once it had been adopted. He was president of the committee that drafted Delaware's constitution in 1776. In 1777 he replaced John McKinly, captured by the British, as Delaware's governor. He became Judge in Court of Appeals in admiralty cases and was elected State Senator under the new constitution. He became Chief Justice of the State of Delaware in 1793, serving until his death.