Complex sentence: Photographic history had tended to focus on male photographers such as Stieglitz, and less so on the female photographers, even though it was one of the few occupations considered a respectable career for a single woman in turn of the century New York.
Split into simpler sentences: Photographic history had tended to focus on male photographers such as Stieglitz, and less so on the female photographers. Photography was one of the few occupations considered a respectable career for a single woman in turn of the century New York.