It displayed art-works that had been rejected by the Académie française when submitted for display at the 'Salon': the official exhibition of the French Academy of Art.
In 1863 the nascent Realist and Impressionist movements submitted works to the Academy's selection committee only to be rejected. The resultant complaints of bias led the French emperor Napoleon III to allow the rejected works to be displayed in a separate exhibition.
Most were undoubtedly of poor quality, leading to ridicule in the press. However, the exhibition contained at least two important paintings, Edouard Manet's "Dejeuner sur l'Herbe" (the 'Picnic') and James McNeill Whistler's "The White Girl".