Portrait of Frederick Muschenheim by Arnold Genthe

Brother to William, Frederick, or Fred as he was commonly called, partnered with William in the creation of the Astor Hotel. He was tasked with gathering the items that would eventually decorate the American Indian Hall, and, as a graduate of the Stevens Institute of Technology in New Jersey, he also designed many of the internal systems of the hotel, such as sensors in the front desk's mail slots that would alert a guest in their room when they got a letter. Fred became proprietor upon William's death. Fred's son, William, was a Modernist architect who worked on a number of redesigns for the hotel in the 1930s, drawings for which are housed at Columbia University and the University of Michigan.