The American Anti-Imperialist League was an organization established on June 15, 1898, to battle the American annexation of the Philippines as an insular area. The anti-imperialists opposed expansion, believing that imperialism violated the fundamental principle that just republican government must derive from "consent of the governed."
The argument made by anti-imperialists in the late 1800s was that the United States: might have to go to war over distant territories.