Maurice Wertheim

In 1909, he married Alma Morgenthau, daughter of Henry Morgenthau Sr. They had three daughters, Josephine Wertheim Pomerance (b. 1910), mother of Rafe Pomerance; historian Barbara W. Tuchman (1912–1989), mother of Jessica Mathews; and Anne Rebe Wertheim Werner (1914–1996), previously married to Robert E. Simon.

Alma herself had her own philanthropic interests and, in 1923, was one of the founding members of the League of Composers, also subsidizing its journal, Modern Music, with 1500 annually. She supported publishing the first musical compositions of Aaron Copland, on her Cos Cob Press. She also collected work by Georgia O'Keeffe, and, together, the couple supported the Intimate Gallery. They divorced in 1929.

Following their divorce, Alma founded and supported The Cos Cob Press (eventually bought by Boosey and Hawkes) in 1929 to publish works of contemporary American composers. In 1934 she married Paul Lester Wiener (they divorced in the 1940s) and she died in 1953.

Wertheim married Ruth White in March 1930; they did not have children and divorced in 1935 (she remarried Alexander Smallens in 1935). He was married for a third time in 1944 to Cecile Berlage, who was his spouse until his death; they did not have children.

Wertheim's granddaughter, Betsy Ann Langman, was married to film producer Budd Schulberg. His granddaughter, Lynn Langman married attorney and philanthropist, Philip H. Lilienthal, in 1963.