Answer: Mark Twain and Andrew Carnegie
Step-by-step explanation:
The Anti-imperialist league was founded on June 15, 1898, to oppose the U.S. annexation of the Philippines, claiming economic, legal, racial and moral grounds.
Along with Andrew Carnegie and Mark Twain, there were many famous characters between its members such as William James, David Starr Jordan, Samuel Gompers, and George S. Boutwell.