Columbia subject headings:
Mexican-American Border Region--History--20th century.
Mexico--History--Revolution, 1910-1920.
Postcards--United States--History--20th century.
United States. Army--History--Punitive Expedition into Mexico, 1916.
Harvard subject headings:
Princeton subject headings:
Mexican-American Border Region--History--20th century.
Mexico--History--Revolution, 1910-1920.
Postcards--United States--History--20th century.
United States. Army--History--Punitive Expedition into Mexico, 1916.