Alfred Stieglitz exhibited Georgia O'Keeffe's work at his New York gallery, 291, in 1916.
The gallery was officially known as the Little Galleries of the Photo-Secession and became widely identified by its address at 291 Fifth Avenue. Stieglitz first encountered O'Keeffe's abstract charcoal drawings through the artist and teacher Anita Pollitzer. Without O'Keeffe's permission, Pollitzer showed them to Stieglitz, who recognized their originality.
Stieglitz included O'Keeffe's work in a group exhibition at 291 in 1916. He then presented her first solo exhibition there in 1917. Their professional relationship became personal, and they married in 1924. Stieglitz continued to promote her art through exhibitions and photographs.
A common mix-up is to call 291 the Armory Show. The 1913 Armory Show was a separate, much larger exhibition organized by different people. The name 291 refers to the gallery's address and is the concise answer associated with O'Keeffe's early New York breakthrough.