Many of the Filipinos who led the revolution against Spain in the 1890s were ilustrados. Ilustrados, almost without exception, came from wealthy Filipino families that could afford to send them to the limited number of secondary schools (colegios) open to non-Spaniards. Some of them went on to the University of Santo Tomás in Manila or to Spain for higher education. Although these educational opportunities were not available to most Filipinos, the Spanish colonial government had initiated a system of free, compulsory primary education in 1863. By 1898 enrollment in schools at all levels exceeded 200,000 students.
Between 1901 and 1902, more than 1,000 American teachers, known as "Thomasites" for the S.S. Thomas, which transported the original groups to the Philippines, fanned out across the archipelago to open barangay schools. They taught in English and, although they did not completely succeed in Americanizing their wards, instilled in the Filipinos a deep faith in the general value of education. Almost immediately, enrollments began to mushroom from a total of only 150,000 in 1900-1901 to just under 1 million in elementary schools two decades later. After independence in 1946, the government picked up this emphasis on education and opened schools in even the remotest areas of the archipelago during the 1950s and the 1960s.