Columbia subject headings:
United States--History--Civil War, 1861-1865.
United States--History--Revolution, 1775-1783.
World War, 1914-1918--United States--Influence.
World War, 1939-1945--United States--Influence.
Harvard subject headings:
United States--History--Civil War, 1861-1865--Social aspects.
United States--History--Revolution, 1775-1783--Social aspects.
World War, 1914-1918--Social aspects--United States
World War, 1939-1945--Social aspects--United States.
Princeton subject headings:
United States--History--Civil War, 1861-1865--Social aspects.
United States--History--Revolution, 1775-1783--Social aspects.
World War, 1914-1918--Social aspects--United States.
World War, 1939-1945--Social aspects--United States.