He became active in the nationalist movement in the early 1890s and led an armed uprising against Spanish rule (1895–96). He returned during the Spanish–American War (1898) and organized another guerrilla campaign, but, after the US victory, his nationalist aspirations resulted in war with American forces (1899–1901). Finally accepting US rule, he waged a peaceful campaign for independence for the next four decades before collaborating with the Japanese during World War II. Briefly imprisoned by the Americans in 1945, he retired from active politics after his release.