[1] Loeb was born to a Jewish family on November 11, 1902, in St. Louis, Missouri, the son of Adeline (née Moses) and Carl M.

[1][2] His father was an immigrant from Germany who made a fortune after gaining control of the American Metal Company (founded by Berthold Hochschild and Jacob Langeloth).

[1] In 1931, he and his father co-founded the Carl M. Loeb & Company in order to manage the family's holdings with the firm paying $250,000 to become a member of the New York Stock Exchange.

[1] In 1964, he organized the National Independent Committee for President Lyndon B. Johnson and Senator Hubert H.

[1] He operated the Loeb Partners Corporation, a boutique investment banking firm.

[1] Loeb served as the chairman of the Institute of Fine Arts, a trustee of the Museum of Modern Art, as chairman and chief executive of the Jacob and Valeria Langeloth Foundation, and as a member of the Harvard Board of Overseers.

[1][8] He and his wife were collectors of French Impressionist paintings including Manet, Pissarro, Degas, Cézanne, and Renoir.