USA vs American Civil War

USA and American Civil War both are nouns.

Word	Noun	Adjective	Verb	Adverb
USA	Yes	No	No	No
American Civil War	Yes	No	No	No

USA (noun)	American Civil War (noun)
the army of the United States of America; the agency that organizes and trains soldiers for land warfare	civil war in the United States between the North and the South; 1861-1865
North American republic containing 50 states - 48 conterminous states in North America plus Alaska in northwest North America and the Hawaiian Islands in the Pacific Ocean; achieved independence in 1776