In 1915, Barangay CASOOCAN is a place that was inhabited by three families: namely Nicolas Socito and brother Jacinto Socito plus a certain Juan Arcilla. Their houses were situated in a hidden corner near the road going to Barangay Igang. The people from Antipolo and Magnesia when ask where they are going; they will answer “duman sa sook”.

Lately as the inhabitants in this place grow in number, the name “Sook” was converted into Casoocan. This barangay can be called Casoocan because it is surrounded by forests and mountain. They are far from the sea unlike the adjacent barangay in Talisoy. Scientifically speaking their geographical location coincides with the barangay’s name. This was only a sitio of barangay Magnesia.

Then in 1937, during the term of the late Mayor Florencio Tacorda (alias hamis) it was separated from Magnesia and became a barrio. Starting 1918 this place has already an appointed “barangay captain” formerly called “teniente del barrio”. The pioneer of which was Juan Araojo followed chronologically by Pedro Arcilla, Doroteo Tabinas, Juan Socito, Flaviano David, Pedro Marino, Fidel Tabilog, Jacinto Molina, Gavino Molina (brothers), Pedro Araojo from the poblacion (Ilawod) Felix Arcilla, Nestor David, Honorato Clemente, Pedro Araojo, Efipanio Tabinas term in 1990-1994 with his councilors as: Avelino B. Ramos, Pedro Socito, Jose G. Guerrero, Vicente S. Antonio, Efren T. Gonzales, Rolando M. Traquena, Eustaquio Tabilog, Felicitas Vargas, and Justo Molina.

For two terms from 1994 to 2002, it was maneuvered by Alexander G. Guerrero a bachelor barangay Captain. In his first term in 1994 these were his councilors namely: Relita G. Caballero, Salvacion D. Ramos, Amelita S. Yat, Alfredo R. Araojo, Felecitas M. Vargas, Rolando M. Traquena and Aurora C. Dasigan. Under the same pilot some councilors were re-elected such as Avelino B. Ramos, Rolando M. Traquena, Jose G. Guerrero, Jr., Susana T. Tabinas and Ramon Romero.

In 2002 to 2007, 2010 to 2013, Isidro B. Molina was elected as Punong Barangay. Then it was maneuvered again by PB Alexander G. Guerrero from 2007 to 2010 and from December 2013 up to the present. As the years go by this barangay officials were already elected not anymore appointed up to this time.

One distinguished person found in this place was the late Napoleon S. Marino who became a DECS Regional Director.