The American Anti-Imperialist League was an organization founded in 1898 to protest and combat the nation's forcible overseas expansion. It was formed in direct response to the occupations of Puerto Rico, Cuba and the Philippines.
Though the organization declared itself to be generally against imperialist expansion, a particular emphasis of their platform was the then-current occupation of the Philippines. United States forces entered the country under the pretext of aiding Filipinos in establishing their independence from Spain but then chose to annex the country as a colony of their own, leading to a violent rebellion that the American military suppressed by force.
The organization was founded by Massachusetts banker James McCormick and abolitionist Gamaliel Bradford and had its first meetings in 1898 in Boston. It would eventually expand by enlisting honorary vice presidents who were high-profile public figures. Some prominent examples were Andrew Carnegie, Mark Twain, Grover Cleveland and Samuel Gompers. The organization also made an effort to establish local branches throughout the United States, having the most success in major cities. Despite its anti-war stance, the league did not object to the country's involvement in World War I. The league dissolved in 1920 after a period of waning interest and popularity.