He was born in Princeton, New Jersey and attended Princeton College. He founded a profitable shipping business in Wilmington, North Carolina in 1760. He was elected to the Provincial Assembly in 1766: it was dissolved by the royal governor in 1775. Hewes was appointed to the Committee of Correspondence, elected to the Provincial Legislature, and represented North Carolina at the Continental Congress in 1775.
After signing the Declaration of Independence he placed his ships at the service of the Continental Army. He served as the Secretary of the Naval Affairs Committee of Congress until 1779.