Missouri River vs U.S.

Missouri River and U.S. both are nouns.

Word	Noun	Adjective	Verb	Adverb
Missouri River	Yes	No	No	No
U.S.	Yes	No	No	No

Missouri River (noun)	U.S. (noun)
the longest river in the United States; arises in Montana and flows southeastward to become a tributary of the Mississippi at Saint Louis	the executive and legislative and judicial branches of the federal government of the United States
	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