He was appointed district attorney of San Isidro, Nueva Ecija. He was later elected as governor of Nueva Ecija in 1902 and 1904. His election victory made him the first democratically elected provincial governor and head of the Federal Party in Nueva Ecija. A member of the Philippine Commission, he was immediately considered as one of those Filipino intellectuals to represent the Saint Louis World's Fair in 1904. After his term as the governor, he was appointed provincial fiscal of Bulacan and Bataan provinces. He wrote a treatise on electoral fraud "Electoral Fraud and its Remedies" (Fraudes Electorales y Sus Remedios) in 1907 for the Philippine Assembly. On the side, he devoted his spare time to researches in Philippine history and literature. Portions of his collections where destroyed when fires hit his house in San Isidro, Nueva Ecija. According to Agoncillo and Palma, his interest lies not in politics. In 1918, he was appointed by Gov. Gen. Francis Burton Harrison as Assistant Technical Director of the Philippine Census.