Alfred Stieglitz operated the New York gallery known as 291, where he exhibited Georgia O'Keeffe's work. The gallery was located at 291 Fifth Avenue in Manhattan and was originally called the Little Galleries of the Photo-Secession.
Stieglitz opened the gallery in 1905 to promote photography as a fine art. It soon became an important venue for European avant-garde art and American modernism. The name 291 came from the gallery's street address and became more famous than its longer formal names.
O'Keeffe's first one-person exhibition at a Stieglitz gallery took place in 1917, although 291 itself had closed by then. Her work was shown at the later Intimate Gallery, which Stieglitz opened in the same building. This distinction prevents the common mistake of treating every Stieglitz exhibition as a 291 show.