Portsmouth was settled in 1638 by a group of religious dissenters from Boston Colony, including Dr. John Clarke, William Coddington, and Anne Hutchinson. It is named after Portsmouth, Hampshire, England. Roger Williams convinced the settlers that they should go there, instead of settling in New Jersey, where they had originally planned on going. It was founded by the signers of the Portsmouth Compact. Its original Indian name was Pocasset. It was officially named Portsmouth on May 12, 1639. It became part of the colony of Rhode Island and eventually of the colony of Rhode Island on Providence Plantations and the state that bears that name.
Portsmouth is the site of an important capture during the American War for Independence. Lieutenant Colonel William Barton of Rhode Island captured the British Commander at Rhode Island, General Richard Prescott, there. It is also the site of Rhode Island’s only major battle in that war on Butt’s Hill. Nearby Founder’s Brook is said to have run red with the blood of fallen British soldiers on August 29, 1778. During the Battle of Rhode Island, the 1st Rhode Island Regiment, which compost mostly of African-American soldiers, served in the army of General John Sullivan.