He was born on the 22d of April, 1846, in New Jersey, a son of John T. and Mercy (Howell) Hart. The former was born in Sussex county, New Jersey, and the latter in Warren county, that state. The paternal grandfather was John Hart of New Jersey, of English descent, the family emigrating to this country from England in the pre Revolutionary period. The maternal grandfather was Levi Howell and he came of Dutch ancestry.