Family lore told privately of the firstborn son, Manny, born in 1886 but surviving for only three months, and carried off by tuberculosis. Even some members of the Marx family wondered if he was pure myth, but Manfred can be verified: a death certificate of the Borough of Manhattan reveals that he died, aged seven months, on 17 July, 1886, of enterocolitis, with "asthenia" contributing, i.e., probably a victim of influenza. He is buried at New York's Washington Cemetery, beside his grandmother, Fanny Sophie Schönberg (née Salomons), who died on 10 April, 1901.