REMOVE

1. Photographs
2. Portrait photographs
3. Acetate negatives
4. Photographers.
5. Library of Congress Prints a …

WHAT

1. Acetate negatives (1)
2. Portrait photographs (1)
3. negative (1)

WHO

1. Library of Congress Print … (1)
2. Unknown (1)

WHEN

1. 1911 (1)
2. 1942 (1)
3. between 1911 and 1942 (1)