When Marcel Duchamp arrived in New York in October 1926 with a consignment of Brancusi sculptures for a one-man exhibition of the sculptor's work, a series of events began which resulted in a new definition of art in America. The American Customs authorities denied Brancusi's sculptures the duty-free entry which normally applied to works of art, on the grounds that the works did not appear to be sculpture. Duchamp appealed on Brancusi's behalf, and the resulting trial, Brancusi vs. United States, became famous as the moment at which the legal definition ora work of art changed to embrace the modern.

The trial focussed around the 1923 work, Bird in Space. Slender, tapered and bronze in color, with a mirror-like surface, to the authorities it appeared to be some kind of industrial object, certainly not one with the characteristics of art:

Q: Why do you regard Exhibit I as not a work of art?

A: It is too abstract and a misuse of the form of sculpture... I don't think it has the sense of beauty.

Q: ... If it had been given a head to it would that have arou