The Anti-Imperialist League and American Expansionism

The Rise of American Imperialism After the Spanish-American War

At the close of the 19th century, the United States shifted from a policy of isolationism to one of imperialism, a change that was particularly evident after the Spanish-American War of 1898. The war, which was influenced by the mysterious explosion of the U.S.S. Maine in Havana Harbor and America's support for Cuban independence, ended with a decisive U.S. victory. The Treaty of Paris, concluded in December 1898, not only ended the conflict but also resulted in the cession of former Spanish colonies—Puerto Rico, the Philippines, Guam, and an occupation of Cuba—to the United States. Spain was compensated with $20 million for the Philippines, signaling a new era in American foreign policy and overseas expansion.

The Emergence and Expansion of the Anti-Imperialist League

The expansionist actions of the United States following the war sparked domestic opposition. The Anti-Imperialist League was formed on June 15, 1898, in Boston, initially as a regional organization that quickly grew into a national movement with tens of thousands of members. Founded by individuals like Gamaliel Bradford, the League opposed the annexation of territories such as the Philippines and Puerto Rico, arguing that such actions were contrary to the American principles of freedom and self-determination as enshrined in the Declaration of Independence.