Marcel Duchamp can be given much of the credit or blame for how the current art situation came to be. His contributions were critical in the development of almost all later are movements
Unlike so many of his followers, Duchamp could actually draw. This early sketch of his brother, Jacques Villon, shows tremendous skill and manages to display motion that will be fundamental in the artist's later masterpieces.
Duchamp's Portrait of Chauvel from 1910 show a clear influence of Fauvism.
Sad Young Man in a Train from 1911 represents a tremendous breakthrough for Duchamp.
Nude Descending a Staircase #1 from 1911
It was Nude Descending a Staircase #2 from 1912 that really established Duchamp's career. When it was displayed in the Armory show in New York in 1913 the artist became internationally known.
The artist was associated with the Dada movement. Many of the groups publications can be found here.