Should American Be Capitalized?

Generally, no matter what part of speech the term “American” represents, it should always be capitalized. I will leave you with the following two examples of how the word can be used as both a proper noun and proper adjective.

Should Americans always be capitalized?

Yes, "American" is a proper noun, a word for a specific nationality. A proper noun is always capitalized.

Is the word America a proper noun?

America (proper noun)