Soon he was on his way to fight Emilio Aguinaldo's Insurrectos as part of Major General Arthur MacArthur, Jr.'s 2nd Infantry Division. He took part in the advance from Angeles City to Tarlac City, Aguinaldo's capital. But Aguinaldo had fled, and the 12th Infantry pursued him vainly all the way through Luzon's central plain to Dagupan City.[3] While serving in an infantry unit in the Philippines, he was promoted to sergeant.