His early landscapes, which show the influence of the Barbizon School and of Corot, George Inness and Albert Pinkham Ryder gained him little recognition from critics or the public.

[5] His later, visionary works depicting moonlit landscapes populated with voluptuous nymphs caused his contemporaries particular consternation, due to their crudely rendered and often extravagantly smiling nudes.

Eilshemius also wrote verse and prose, composed music, painted, philosophized and became notorious for his numerous, often vitriolic, letters-to-the-editor of various New York City publications.

On letterheads and in hyperbolic, self-published flyers he would proclaim his accomplishments: "Educator, Ex-actor, Amateur All-around Doctor, Mesmerist-Prophet and Mystic, Reader of Hands and Faces, Linguist of 5 languages", as well as world-class athlete and marksman, "Spirit-Painter Supreme", and musician whose improvisations rivaled the compositions of Chopin.

"[5] Victor Ganz started collecting art in his teenage years with the purchases of watercolors by Louis Eilshemius and Jules Pascin and an oil painting by Raphael Soyer.

According to Stefan Banz, there is no evidence that Eilshemius was a grandson of Swiss painter Louis Léopold Robert as some sources report.