Although the Thomasites were the largest group of pioneers with the purpose of educating the Filipinos, they were not the first to be deployed by Washington, D.C. A few weeks before the arrival of USS "Thomas", U.S. Army soldiers had already begun teaching Filipinos the English language, thus in effect laying the foundation of the Philippine public school system. The U.S. Army opened the Philippines' first public school in Corregidor Island, after Admiral George Dewey vanquished the Spanish Pacific fleet in Manila Bay on May 1, 1898. Also, a few weeks before the arrival of USS "Thomas", another group composed of 48 American teachers also arrived in the Philippines, aboard the "USAT Sheridan".