He was born in New Castle, Delaware and educated at home. He read law at his brother John's law office and was admitted to the bar in Philadelphia. Initially a Tory, he served as Crown Prosecutor for twelve years and was elected to the provincial legislature in 1768. There his sympathies began to change and he became a strong supporter of the colonial assemblies in their disputes with Parliament. He was a member of the Committee of Safety and was elected to the Continental Congress. He was a Colonel in the Continental Army, and vice-president of the first constitutional convention for Pennsylvania. He resigned from the Continental Congress in 1777 because of poor health, and was appointed to the Pennsylvania Court of Admiralty, in which office he died.