America vs Union

America and Union both are nouns.

Word	Noun	Adjective	Verb	Adverb
America	Yes	No	No	No
Union	Yes	Yes	No	No

America (noun)	Union (noun)
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	the United States (especially the northern states during the American Civil War)
North America and South America and Central America

America (adjective)	Union (adjective)
	being of or having to do with the northern United States and those loyal to the Union during the American Civil War