Columbia subject headings:
Frontier and pioneer life--United States--Bio-bibliography.
Historians--United States--Biography.
United States--Territorial expansion--Bio-bibliography.
Harvard subject headings:
Frontier and pioneer life--United States--Bio-bibliography.
Historians--United States--Biography
United States--Territorial expansion--Bio-bibliography.
Princeton subject headings:
Frontier and pioneer life--United States--Bio-bibliography.
Historians--United States--Biography.
United States--Territorial expansion--Bio-bibliography.