The first-ever elections to Philippine Senate were held on October 3, 1916, immediately after the passage of the Philippine Autonomy Act, known as the
Jones Law. The Act created the
Senate of the Philippines. The Senate replaced the
Philippine Commission as the
upper house of the
Philippine Legislature, thus creating for the first time a fully elected national
legislative branch in the Philippines, under the American colonial
Insular Government. Each district elected two senators (plurality-at-large): The first-placer was to serve a six-year term while the second-placer was to serve a three-year term. On each election thereafter, one seat per district was up (first past the post). The senators from the
12th district were appointed by the American
governor-general for no fixed term.