History of Division of the Philippines into Provinces

When the United States acquired the Philippines from Spain in 1898, the islands were divided into four gobiernos, which were further subdivided into provinces and districts. The American administration initially inherited the Spanish divisions and placed them under military government. As insurgencies were pacified, civil government was gradually restored.
1901-06-11: Morong district merged with part of Manila Province to form Rizal Province.
1902: Mindoro merged with Marinduque; Amburayan province split from La Union; later, Marinduque province merged with Tayabas.
1903: Moro Province formed, consisting of the districts of Cotabato, Davao, Lanao, Sulu, and Zamboanga. Its capital was the town of Zamboanga.
1905: Name of Paragua province changed to Palawan. Masbate province merged with Sorsogon.
1907: Romblon merged with Capiz; split from it again in 1917.
1907-08-20: Agusan province split from Surigao.
1908: Abra province merged with Ilocos Sur; split from it again on 1917.
1908-08-13: Mountain Province formed by merging the provinces of Amburayan, Apayao, Benguet, Bontoc, Ifugao, Kalinga, and Lepanto, which became its sub-provinces.
1909: Batanes province split from Cagayan.
1916-08-29: Name and status of Moro Province changed to the Department of Mindanao and Sulu. Status of its districts (Bukidnon, Cotabato, Davao, Lanao, Sulu, and Zamboanga) changed to provinces.
1917-03-10: Most of the pre-war provinces formally established or re-established. Ambos Camarines province divided into Camarines Norte and Camarines Sur provinces; Abra and Romblon re-established.
1920-02-21: Marinduque province split from Tayabas.
1920-12-15: Masbate province split from Sorsogon.
1921-02-20: Mindoro province split from Marinduque.
1923-03-27: Leyte divided into Occidental Leyte and Oriental Leyte by law, but never proclaimed by the governor-general.
1929-11-02: Misamis province divided into Misamis Occidental and Misamis Oriental provinces (implemented 1939-11-28).
1945-09-26: Catanduanes province split from Albay.
1946: Romblon province merged again with Capiz; split from it again on 1947-01-01.
1946-09-07: Name of Tayabas province changed to Quezon.
1950-06-13: Mindoro province split into Mindoro Occidental and Mindoro Oriental.
1952-06-06: Zamboanga province split into Zamboanga del Norte and Zamboanga del Sur.
1956-04-25: Aklan province split from Capiz (implemented 1956-11-08).
1959-05-22: Lanao province divided into Lanao del Norte and Lanao del Sur; Southern Leyte province split from Leyte.
1960-06-19: Surigao province divided into Surigao del Norte and Surigao del Sur provinces.
1965-06-19: Samar province divided into Eastern Samar, Northern Samar, and Western Samar.
1966-06-18: South Cotabato province split from Cotabato; Benguet, Ifugao, and Kalinga-Apayao provinces split from Mountain Province; Camiguin province split from Misamis Oriental.
1967-05-08: Davao province divided into Davao del Norte, Davao del Sur, and Davao Oriental provinces (implemented 1967-07-01).
1967-06-17: Agusan province divided into Agusan del Norte and Agusan del Sur provinces (implemented 1970-01-01).
1969-06-21: Name of Western Samar province changed to Samar.
1969-08-04: Samal sub-province created from Davao del Norte but never inaugurated.
1971-09-10: Quirino province split from Nueva Vizcaya.
1971-10-04: Maranaw province created from Lanao del Sur but never inaugurated.
1972-01-08: Siquijor province split from Negros Oriental.
1972-06-17: Name of Davao del Norte province changed to Davao.
1973-09-11: Tawi-Tawi province split from Sulu.
1973-11-22: Cotabato province divided into Maguindanao, North Cotabato, and Sultan Kudarat provinces.
1973-12-27: Status of Basilan changed from chartered city to province.
1975-11-08: Metro Manila established from four chartered cities, and towns of Rizal and Bulacan.
1979-08-13: Aurora province split from Quezon, following a plebiscite.
1983-12-19: Name of North Cotabato province changed to Cotabato.
1986-01-03: Negros del Norte province split from Negros Occidental.
1986-08-18: Negros del Norte creation found unconstitutional by the Supreme Court, reverts as part of Negros Occidental.
1992-03-16: Sarangani province split from South Cotabato.
1992-05-11: Biliran province split from Leyte; Guimaras province split from Iloilo.
1995-02-14: Kalinga-Apayao province split into Kalinga and Apayao provinces.
1998-03-07: Compostela Valley province split from Davao province. Name of Davao province changed back to Davao del Norte.
2001-02-23: Zamboanga Sibugay province split from Zamboanga del Sur.
2006-08-30: Shariff Kabunsuan province split from Maguindanao.
2006-10-02: Dinagat Islands province split from Surigao del Norte.
2008-11-18: Shariff Kabunsuan creation found unconstitutional by Supreme Court, reverts as part of Maguindanao.

HISTORY: PART OF MY ADVENTURE