In the wake of pacification[REF] and the significant changes that came after it, such as the establishment of the First Philippine Assembly (a unicameral legislature), Peñaranda ran for a seat in the Assembly and was elected representative of the Third District (now Second District) of Leyte in 1904.
At the First Philippine Assembly, Peñaranda was a member of various committees including agriculture, Civil Service, Navigation, and Provincial and Municipal Governments.