USA vs Mississippi

USA and Mississippi both are nouns.

Word	Noun	Adjective	Verb	Adverb
USA	Yes	No	No	No
Mississippi	Yes	No	No	No

USA (noun)	Mississippi (noun)
the army of the United States of America; the agency that organizes and trains soldiers for land warfare	a state in the Deep South on the gulf of Mexico; one of the Confederate States during the American Civil War
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	a major North American river and the chief river of the United States; rises in northern Minnesota and flows southward into the Gulf of Mexico