Cubism:

The subsequent 1912 Salon des Indépendants was marked by the presentation of Marcel Duchamp's Nude Descending a Staircase, No. 2, which itself caused a scandal, even amongst the Cubists. It was in fact rejected by the hanging committee, which included his brothers and other Cubists. Although the work was shown in the Salon de la Section d'Or in October 1912 and the 1913 Armory Show in New York, Duchamp never forgave his brothers and former colleagues for censoring his work. Juan Gris, a new addition to the Salon scene, exhibited his Portrait of Picasso (Art Institute of Chicago), while Metzinger's two showings included La Femme au Cheval (Woman with a horse) 1911-1912 (National Gallery of Denmark). Delaunay's monumental La Ville de Paris (Musée d'art moderne de la Ville de Paris) and Léger's La Noce, The Wedding (Musée National d'Art Moderne, Paris) were also exhibited.

Please answer a question about this article. If the question is unanswerable, say "unanswerable". What painting of Duchamp's was not controversial?
unanswerable