After the dissolution of the republic, Zamboanga was eventually consolidated into one major administrative area by the American government of the Philippines, consisting of an enormous region that was the Mindanao island's western peninsula, Basilan Island, and the entire Sulu archipelago, with the ancient namesake town/fort of Zamboanga as the seat of its government, and was called the Moro Province of the Philippines.

In 1920, the Department of Mindanao and Sulu was officially dissolved and Zamboanga became an independent province.

After the war, on June 16, 1948, Molave was designated as Zamboanga's capital by the virtue of Republic Act No.

The bill was signed by President Elpidio Quirino in a ceremony held at the Malacañan Palace.

The towns of Dapitan, Dipolog, Rizal, New Piñan, Polanco, Katipunan, Manukan, Sindangan, Liloy, Labason and Siocon are composed of the province of Zamboanga del Norte.