The Philippine–American War (1899–1902) was an armed conflict between a group of Filipino revolutionaries and the American forces following the ceding of the Philippines to the United States after the defeat of Spanish forces in the Battle of Manila. The Army sent in 100,000 soldiers (mostly from the National Guard) under General Elwell Otis. Defeated in the field and losing its capital in March 1899, the poorly armed and poorly led rebels broke into armed bands. The insurgency collapsed in March 1901 when the leader Emilio Aguinaldo was captured by General Frederick Funston and his Macabebe allies. Casualties included 1,037 Americans killed in action and 3,340 who died from disease; 20,000 rebels were killed.