Jacob Schiff
Although a major factor in German finance, after frequent business trips to New York Warburg settled there in 1902 as a partner in Kuhn, Loeb &amp; Co., where the influential Jacob Schiff was senior partner. Paul's brother, Felix, was married to Schiff's daughter and both brothers would be involved with Kuhn, Loeb over the years, making partner after marrying into the firms family members.. Warburg remained a partner in the family firm in Hamburg, but he became a naturalized American citizen in 1911. He was a member of Temple Emanu-El in New York City.