Legislative districts of Mindanao and Sulu

Initially being excluded from representation in the lower house of the Philippine Legislature in 1907, the then-non-Christian-majority areas of the Philippines — which included the Department of Mindanao and Sulu's seven component provinces; Nueva Vizcaya; the Mountain Province; and Baguio — were finally extended legislative representation with the passage of the Philippine Autonomy Act in 1916 by the United States Congress.

[1] The non-Christian areas were to be collectively represented in the upper house's 12th senatorial district by two senators, both appointed by the Governor-General.

[1] Five assembly members, also appointed by the Governor-General, were to represent the seven component provinces of Department of Mindanao and Sulu — Agusan, Bukidnon, Cotabato, Davao, Lanao, Sulu and Zamboanga — in the lower house as a single at-large district.

Voters of the more Christianized provinces of Agusan, Bukidnon, Davao and Zamboanga could elect their representative through popular vote by virtue of Article VI, Section 1 of the 1935 Constitution.

[4] In the Muslim-dominated provinces of Cotabato, Lanao and Sulu, however, voter qualifications were more restrictive: the only persons allowed to vote for the province's representative were past and present municipal officials (municipal president, vice-president, municipal councilors); present senators, assembly representatives and 1935 Constitutional Convention delegates; provincial governors and members of provincial boards; and any persons currently residing in the concerned province who held any of the aforementioned positions in the past.