USA vs Bluegrass State

USA and Bluegrass State both are nouns.

Word	Noun	Adjective	Verb	Adverb
USA	Yes	No	No	No
Bluegrass State	Yes	No	No	No

USA (noun)	Bluegrass State (noun)
the army of the United States of America; the agency that organizes and trains soldiers for land warfare	a state in east central United States; a border state during the American Civil War; famous for breeding race horses
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