Born in Bavaria, Jacob (also called Naphtali) Hart emigrated to the United States in his early twenties, arriving in Baltimore by 1768—the first known Jew to settle in the city, which was then just forty years old. He quickly established himself as a merchant of substance and aligned himself with the Patriot cause during the Revolutionary War. When General Lafayette itemized the needs of the Continental Army during a 1781 visit to Baltimore, Hart donated £2,000—the single largest contribution to the local subscription in support of the cause.

In 1778, Hart, then thirty-two, married Philadelphia-born Leah Nathan, the 18 year old daughter of Lyon Nathan and his wife Caroline Webb, a convert to Judaism. The bride’s father was then serving as shammas of Congregation Mikveh Israel in Philadelphia. The newlyweds moved between Philadelphia and Baltimore for the first few years of their marriage but by 1787 they had settled in New York, where the last 9 of their 13 children were born. Hart himself would emerge as an important member of the New York Jewish community, ultimately serving as parnas of Shearith Israel. Among their children were Nathan and Rebecca, who married the actor Moses Phillips. Hart’s ties to the Revolution were cemented in 1809, when his twenty-two-year-old daughter Ella married Haym Moses Salomon, youngest son of the late financier of the Revolution who had died in 1785.