USA vs Maryland

USA and Maryland both are nouns.

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

USA (noun)	Maryland (noun)
the army of the United States of America; the agency that organizes and trains soldiers for land warfare	a Mid-Atlantic state; one of the original 13 colonies, with capital Annapolis
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	one of the British colonies that formed the United States, with capital Annapolis