In 1895, Morris was married to Alice Vanderbilt Shepard (1874–1950). She was the daughter of Elliot Fitch Shepard (1833–1893), a lawyer, banker, and owner of the "Mail and Express" newspaper, as well as a founder and president of the New York State Bar Association, and Margaret Louisa Vanderbilt (1845–1924), who did not approve of her daughter marrying Morris. Alice was a granddaughter of William Henry Vanderbilt. Together, they were the parents of:   Morris died at his home, 19 East 70th Street in Manhattan, on May 4, 1944. His widow died in Bar Harbor, Maine in August 1950.