He was born in Abington, Maryland, and home-schooled. He attended Philadelphia College, graduating at age eighteen with a Masters degree. He studied law in Annapolis at a law office and obtained further training at the Inner Temple in London.
He organized politically against a poll-tax imposed by the royal governor prior to the outbreak of the American Revolutionary War and became a prominent leader in the patriot movement.
He was elected to the Maryland legislature in 1771 and appointed to the Continental Congress in 1774. He was reelected, serving until 1779, when he became chief justice of the state of Maryland. In 1782 he was elected governor of Maryland. In 1789 he became federal district judge for the state of Maryland, and served as such until his death.