REMOVE

1. World War, 1914-1918.
2. Mammoths.
3. Drawing
4. War allies.
5. Rogers, W. A.
6. Library of Congress Prints a …

WHAT

1. Drawings and Watercolors (1)
2. Uncle Sam (Nickname) (1)
3. War allies. (1)

More 

WHO

1. Library of Congress Print … (1)
2. Rogers, W. A. (1)

WHEN

1. 1854-1931 (1)
2. 1917 (1)
3. 1917? (1)