Alfred Stieglitz’s influential New York gallery was called 291.
The gallery took its name from its address at 291 Fifth Avenue in Manhattan. Stieglitz operated it from 1905 to 1917, first as the Little Galleries of the Photo-Secession and later under the shorthand name 291. It became a major venue for photography and European avant-garde art.
O'Keeffe’s work was shown there after Stieglitz received photographs of her drawings in 1916. The exhibitions helped introduce her to New York’s art world and began the association that led to their marriage in 1924. Her early abstractions at 291 differed from the flower paintings for which she later became widely known.
The number 291 can be confused with Stieglitz’s later galleries. After 291 closed, he operated the Intimate Gallery and then An American Place. Those were separate venues, although all belonged to the same broader effort to support modern art in the United States.