Petersburg vs American Civil War

Petersburg and American Civil War both are nouns.

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

Petersburg (noun)	American Civil War (noun)
the final campaign of the American Civil War (1864-65); Union forces under Grant besieged and finally defeated Confederate forces under Lee	civil war in the United States between the North and the South; 1861-1865
a town in southeastern Virginia (south of Richmond); scene of heavy fighting during the American Civil War