Answer: The anti-imperialists opposed the expansion because they believed imperialism violated the credo of republicanism, especially the need for "consent of the governed".
Explanation:
The Anti-Imperialist League was founded on June 15, 1898, in Boston in opposition of the acquisition of the Philippines, which happened anyway. The anti-imperialists opposed the expansion because they believed imperialism violated the credo of republicanism, especially the need for "consent of the governed".