A person who opposes the formation or maintenance of a confederation of united states or groups.
From anticonfederationism + -ist (one who practices or advocates). The suffix -ist transforms ideologies into person-labels, a pattern that became standard in political terminology during the 19th century.
The Anti-Federalists in early American history weren't technically 'anticonfederationists,' but these were the people who feared a strong federal government would crush individual state power—the word perfectly describes their political stance.
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