In 1877, he started his first business in Passaic, New Jersey, and later started work at the wholesale clothing firm of his father, David Marks & Sons.

He later served also as trustee of the Hospital Saturday and Sunday Association, director of the Educational Alliance, member of the Conciliation Committee of the National Civic Federation, director of the National Butchers' and Drovers' Bank.

Louis’ son was songwriter Johnny Marks (1909-1985), who wrote “Rudolph the Red-Nosed Reindeer”.

[6] Marcus and Esther Marks had two daughters: Bernice Marks married (and divorced) Robert B. Stearns, co-founder of Bear Stearns.

[7][8] Doris Marks married industrial designer Henry Dreyfuss.