Charles Carroll was born on September 19, 1737, in Annapolis, Maryland. The child of a prominent family, he was educated in Paris and London, where he studied civil law. He returned to Maryland in 1765 to assume control of the family estate, one of the largest in the colonies. At that time he added "of Carrollton" to his name to distinguish himself from his father and cousins of the same name. As a Roman Catholic, he was barred from entering politics, practicing law, and voting. However, writing in the Maryland Gazette under the pseudonym "First Citizen," he became a prominent spokesman against the governor's proclamation increasing legal fees to state officers and Protestant clergy. Carroll served on various committees of correspondence.
He was commissioned with Benjamin Franklin and Samuel Chase in February 1774 to seek aid from Canada. He was appointed a delegate to the Continental Congress on July 4, 1776, and signed the Declaration of Independence. He resigned in 1778 to serve in the Maryland State Assembly and helped draft the Maryland constitution.
Carroll served as Maryland's first Senator from 1789 to 1792, but retired to manage his extensive estates, work for a canal to the West and serve on the first Board of Directors of the Baltimore & Ohio Railroad. He died on November 14, 1832, the last surviving signer of the Declaration of Independence.