I&S Wormser was a New York City-based banking and stock-brokerage house. I&S stood for the brothers Isidor and Simon, who emigrated to the US from Germany when they were teenagers. They initially went to California for the gold rush by sailing around the horn with merchandise they would sell in Sacramento. They prospered early and in 1870 moved to New York to establish what would become a very successful and well known banking business. The Wormser brothers were significant members of the New York establishment.