Prior to gaining separate representation, areas now under the jurisdiction of Maguindanao were represented under the Department of Mindanao and Sulu (1917–1935) and Cotabato (1935–1972).
Maguindanao (including Cotabato City) first gained separate representation in 1984, when it returned two representatives, elected at large, to the Regular Batasang Pambansa.
Under the new Constitution which was proclaimed on February 11, 1987, the province, including Cotabato City, was reapportioned into two congressional districts;[2] each elected its member to the restored House of Representatives starting that same year.
The province of Shariff Kabunsuan, established with the passage of Muslim Mindanao Autonomy Act No.
[3] It was this specific provision that became the subject of the Supreme Court case that ultimately voided MMA Act No.