While Arrangement in Black and Gray (portrait of the artist's mother (Whistler's Mother} could be considered his most famous work, his most influential would have to be Nocturne in Black and Gold: The Falling Rocket. This painting was criticized by critic John Ruskin as a "pot of paint" flung in the viewer's face. (This painting is not very realistic, and is barely identifiable without the "rocket" part of the title.)

Whistler sued Ruskin for slander, saying "Painting should exist for its own sake, not to convey moral or literary ideas" and "Art should be independent of all claptrap... should stand alone and appeal to the artistic sense of eye or ear, without confounding this with emotions entirely foreign to it, as devotion, pity, love, patriotism and the like. All of these have no kind of concern with it, and that is why I insist on calling my works 'arrangements' and 'harmonies'".

Whistler won his case, but did not make nearly enough money to cover his legal expenses, and was forced to declare bankruptcy.

Ruskin went insane.

Whistler's case would give rise to the "art for art's sake" phenomenon that would influence everyone from Picasso to Jasper Johns. No longer would art be used to copy reality, but to create its own reality.