What was the name of Georgia O'Keeffe's husband, the founder of gallery 291?

The founder of gallery 291 and Georgia O'Keeffe's husband was Alfred Stieglitz. He opened the gallery in New York in 1905 at 291 Fifth Avenue, giving it the name by which it became famous.

Gallery 291 introduced American audiences to European modern art and promoted innovative American artists and photographers. Stieglitz showed works by figures including Pablo Picasso, Henri Matisse, and Paul Cézanne, as well as O'Keeffe.

The gallery closed in 1917, but Stieglitz continued supporting modern art through later galleries. His role was broader than that of a photographer: he was also an organizer, publisher, and influential champion of avant-garde art.