Benedict was the second of six children of Benedict Arnold III (1683–1761) and Hannah Waterman King. He was born in Norwich, Connecticut on January 14, 1741. He was named after his great-grandfather Benedict Arnold. That Benedict Arnold had been governor of the Colony of Rhode Island. Benedict Arnold was also named after his brother Benedict IV, who died in infancy. Out of the six children, only Benedict and his sister Hannah lived to be adults; his other brothers and sisters died of yellow fever when they were still children. Arnold's mother's mother's ancestor was John Lothropp. Lothropp was also the ancestor of at least four U.S. presidents.