When General Vicente Alvarez established Zamboanga as a sovereign republic, the leadership was vested upon its president.

During this period, Zamboanga hosted a number of American regional governors, including General John J. Pershing, who was military commander/governor of the Moro Province from 1909 to 1914.

On September 23, 1936, through Assemblyman Juan Alano, the National Assembly of the Philippines passed Commonwealth Act No.

Although born in Bacolod, Negros Occidental on October 11, 1891, Nicasio Valderrosa spent most of his career in Western Mindanao, mainly in Zamboanga and Basilan.

During his term, he was known for transferring the Moro village from the thriving tourist spot of Cawa-Cawa Boulevard to its present location in Campo Islam.

The street that passes from Gateway Mall all through the Zamboanga City Port is named in honor of Mayor Lorenzo.

During the proceedings, Pelayo thundered the session floor by denouncing vast lands owned by the Japanese in Davao City.

At that time, Davao was nicknamed Davaoaka or the little Tokyo of the Philippines because the Japanese had virtual control of the best agricultural lands and influence in local politics.

Many thought it would be his downfall but was redeemed when the Convention inserted a provision limiting the landholdings of the Japanese contained in Article 13, Section 5: "Save in cases of hereditary succession, no private agricultural land shall be transferred or assigned except to individuals, corporation, or associations qualified to acquire or hold lands of the public domain in the Philippines."

Pelayo's exposé caused Secretary of Agriculture and Natural Resources Eulogio Rodriguez to order a full investigation of the Japanese landholdings in Mindanao which resulted in the cancellation of leases of public agricultural lands which were cultivated and developed by the Japanese.

Subsequently, President Manuel Luis Quezon appointed him mayor of Davao in October 1940 which he served until World War II came to the country in 1941.

A few months later, President Sergio Osmeña sent him to Zamboanga and appointed him as City Mayor in 1945 to reorganize also its civil government there.