Israel Jacobs came from London to Philadelphia in 1739. In Philadelphia he became involved with Mikveh Israel and in the late 1740s or early 50s married Maria Caetana (Zipporah) Nunez Machado, a widow whose first husband, David Mendes Machado, had served as hazzan at the Philadelphia congregation. Of the children from her first marriage, the eldest, Rebecca, had married Jonas Phillips. Israel and Maria had one daughter, Rachel, who would marry Jacob I. Cohen.