REMOVE

1. Nitrate negatives
2. Horseback riding.
3. Library of Congress Prints a …
4. Genthe, Arnold
5. between 1911 and 1936
6. 1869-1942

WHAT

1. Horseback riding. (1)
2. Nitrate negatives (1)
3. Photographs (1)
4. negative (1)

WHO

1. Genthe, Arnold (1)
2. Library of Congress Print … (1)

WHEN

1. 1911 (1)
2. 1936 (1)
3. between 1911 and 1936 (1)