Duchamp's first controversial work, Nude Descending a Staircase, No. 2 (Nu descendant un éscalier n° 2) (1912), depicts the motion of the mechanistic nude with superimposed facets, similar to motion pictures. The painting shows elements of both the fragmentation and synthesis of the Cubists, and the movement and dynamism of the Futurists.

He first submitted the piece to appear at the Cubist Salon des Indépendants, but jurist Albert Gleizes asked Duchamp's brothers to have him voluntarily withdraw the painting, or paint over the title that he had painted on the work and rename it something else. His brothers did approach him with Gleizes' request, and Duchamp quietly refused. Of the incident Duchamp later recalled, "I said nothing to my brothers. But I went immediately to the show and took my painting home in a taxi. It was really a turning point in my life, I can assure you. I saw that I would not be very much interested in groups after that."

Later he submitted the painting to the 1913 Armory Show in New York City, which displayed works of American artists and was the first major exhibition of the modern trends coming out of Paris. American show-goers, accustomed to realistic art, were scandalized, and the Nude was at the center of much of the controversy.

Courtesy of Wikipedia