Confederate States vs Confederate States of America

Confederate States and Confederate States of America both are nouns.

Word	Noun	Adjective	Verb	Adverb
Confederate States	Yes	No	No	No
Confederate States of America	Yes	No	No	No

As nouns, Confederate States and Confederate States of America are synonyms defined as:

Confederate States and Confederate States of America: the southern states that seceded from the United States in 1861

Other synonyms of Confederate States include Confederacy, Dixie, Dixieland, South.

Confederate States (noun)	Confederate States of America (noun)
the southern states that seceded from the United States in 1861	the southern states that seceded from the United States in 1861