Hart immigrated to America, settling in Baltimore in 1775. He established himself as a merchant, and though in America only a year at the outbreak of war, aligned himself with the patriot cause. When General Lafayette visited Baltimore in 1791 and told the population of the army's needs, the merchants of the city subscribed for a loan. Jacob Hart was at the head of the list of contributors, with the largest contribution (2000 out of 5,000 pounds contributed).

On November 4, 1778, Hart married Leah Nathan, the daughter of Caroline Webb and Lyon Nathan of Pennsylvania. The couple was married in Philadelphia where Leah’s father served as shammash [caretaker] of Congregation Mikveh Israel. They soon moved to New York where he emerged as an important member of the Jewish community, serving as parnas [president] of Shearith Israel. In 1809, Jacob and Leah’s daughter Ella married Haym Moses Salomon, son of Haym Salomon, who is also represented in Patriots Park.

Hart died on May 9th, 1822 and is buried in the Chatham Square Cemetery of Congregation Shearith Israel in New York.