[1][2] Born in Cuyahoga County, Ohio, to Alexander Loeb, a dry goods merchant, Louis worked at a Cleveland lithography firm from age 14,[2] later taking evening classes in sketching at the Cleveland Art Club.

[2][4] In 1885, he worked at a lithography firm in New York City, with his evenings spent at the Art Students League.

In 1889 he went to Paris to study, under Lefebvre, Constant, and Gérôme, giving up lithography.

After three years, he returned to New York where in 1893 he started work for The Century Magazine as an illustrator.

In 1903 his exhibition of oils at the new rooms of the Cooperative Society in New York aroused interest in his later work.