Letter from Adolph L. Sanger of Isaacs & Sanger, New York City, April 1, 1874 A one-page business letter dated April 1, 1874, written by Adolph L. Sanger of the law firm Isaacs & Sanger. The letter is on the firm's letterhead, indicating their office location at 243 Broadway, Rooms 9 & 10, New York City. The letter also mentions Isaac A. Isaacs and R. B. Regensurger.