Columbia subject headings:
Harvard subject headings:
Africa--Description and travel.
Africa--Discovery and exploration.
America--Discovery and exploration.
Explorers--Africa--Biography.
Explorers--West (U.S.)--Biography
Explorers--West (U.S.)--Biography--19th century.
West (U.S.)--Description and travel.
West (U.S.)--Discovery and exploration.
Princeton subject headings:
Africa--Description and travel.
Africa--Discovery and exploration.
Explorers--Africa--Biography.
Explorers--West (U.S.)--Biography--19th century.
United States--Exploring expeditions.
West (U.S.)--Description and travel.