United Mexican States vs North American country

United Mexican States and North American country both are nouns.

Word	Noun	Adjective	Verb	Adverb
United Mexican States	Yes	No	No	No
North American country	Yes	No	No	No

United Mexican States (noun)	North American country (noun)
a republic in southern North America; became independent from Spain in 1810	any country on the North American continent