United States Civil War vs War between the States

United States Civil War and War between the States both are nouns.

Word	Noun	Adjective	Verb	Adverb
United States Civil War	Yes	No	No	No
War between the States	Yes	No	No	No

As nouns, United States Civil War and War between the States are synonyms defined as:

United States Civil War and War between the States: civil war in the United States between the North and the South; 1861-1865

Other synonyms of United States Civil War include American Civil War.

United States Civil War (noun)	War between the States (noun)
civil war in the United States between the North and the South; 1861-1865	civil war in the United States between the North and the South; 1861-1865