SUBJECT
Discovery and exploration
History
3
Spanish
2
Airplanes, Military
1
America
1
American
1
Biography
1
Christian fiction
1
Drifting ice stations
1
English
1
Explorers
1
Fiction
1
Marines
1
Mississippi River
1
Mississippi River Valley
1
Philippines
1
Politics and government
1
Prototypes
1
Scientists
1
Social life and customs
1
Southwest, New
1
Territorial expansion
1
To 1848
1
United States
1
Voyages and travels
1