A leading proponent of educational modernization, Brumbaugh oversaw reform of the teacher training curriculum for the state of Louisiana. After the American Invasion of Puerto Rico, then a wealthy overseas province of Spain, and the Treaty of Paris of 1899, Brumbaugh was charged with implementation of an American-style educational system in Puerto Rico. Brumbaugh dissolved the entire Education Ministry that had been in place for centuries. Then Brumbaugh had the entire public school faculty, most of whom were trained professors of either Antillean or Peninsular Spanish origins, fired and deported. He then brought from the US a great number of Anglophone school teachers, including his cousin Dr. D. Brumbaugh, considered more "friendly to the American cause". The problem was that the American school teachers spoke only English, and the island's primary language was Spanish, with great numbers of French and Italian speakers. In less than 18 months, after Brumbaugh took over, school absenteeism shot up to 98% with the ensuing performance collapse of a population that spoke one language and the teachers another. Those children who did go to school were punished for speaking Spanish, and put down for their culture. The next thing Brumbaugh did, with the backing of the US Military Government, was to change the entire curriculum, to "Americanize it". He re-wrote the entire Puerto Rican history curriculum, sanitized it and purged from it any data threatening to the "American cause". In addition, he began to edit and doctor data so as to exacerbate anything political or social by the former Spanish Authorities, making it negative, out of context and proportion, in a national humiliation process that caused tremendous public outrage and protests. To this day, the island's educational system is still suffering from Brumbaugh's "reforms". After he left Puerto Rico he held lecturer positions at the University of Pennsylvania and Harvard University. In 1906, he became superintendent of the Philadelphia Public Schools and gained statewide recognition for his performance in this role.