Final answer:
Alfred Stieglitz was the pioneering artist who founded Camera Work magazine in 1905, promoting photography as an art form through his galleries and publications in New York.
Step-by-step explanation:
The artist who was an early crusader for photography and started Camera Work magazine in 1905 New York was Alfred Stieglitz. An influencer in photography and art, Stieglitz devoted himself to elevating the status of photography, showcasing it as a legitimate form of art through his galleries, such as "291", and his publication, Camera Work. His efforts included pioneering new photographic techniques and promoting avant-garde European art, which helped to solidify his reputation in the art world.
Considered a seminal figure in Modern Photography in America, Stieglitz's impact was far-reaching, and his involvement in various New York photographic organizations and the Photo-Secession movement contributed significantly to the acceptance of photography as fine art.