Columbia subject headings:
City and town life--United States--History--19th century.
Ratzel, Friedrich, 1844-1904--Travel--United States.
United States--Civilization--1865-1918.
United States--Description and travel.
Harvard subject headings:
City and town life--United States--History--19th century.
Ratzel, Friedrich, 1844-1904--Journeys--United States.
Ratzel, Friedrich, 1844-1904--Travel--United States.
United States--Civilization--1865-1918.
United States--Description and travel.
Princeton subject headings:
City and town life--United States--History--19th century.
Ratzel, Friedrich, 1844-1904--Travel--United States.
United States--Civilization--1865-1918.
United States--Description and travel.