Isaac Fox was born in 1657 at Concord, Massachusetts, the son of Thomas Fox (ca. 1619-1658), the immigrant, and his second wife, Hannah Brooks. He was reared by his uncle, Timothy Books of Billerica, Massachusetts. He married Abigail Osborn (d. 1718) of Billerica in 1678 and moved to Medford, Massachusetts. They had eight children, 1679-1693. The family moved to New London, Connecticut, in 1698. He married 2) Elizabeth Beebe, daughter of John and Elizabeth York Beebe at Groton, Connecticut, in 1720. He died in 1735. Descendants listed lived in Connecticut, Massachusetts, Vermont, New York, Wisconsin, Nebraska, Minnesota, Michigan, Illinois, Iowa, Kansas, Colorado, Utah, Idaho, Oregon and elsewhere.