[5] Pilar was formerly a barrio known as Banlasan (later renamed Alegria), which is used to be the town center of the municipality of Sierra Bullones.

Constant flooding from Wahig River led residents of Sierra Bullones to transfer their town center at barangay Candagaz and named it as Poblacion.

460 issued by President Carlos P. Garcia, becoming the 45th town in the province[7] Below is list of 16 original barrios of Pilar: Consequently, president Carlos P. Garcia named Demetria B. Buslon and Marcos Auguis as first mayor and vice-mayor of the town respectively.

Also appointed were first councilors Sinoforoso Cabañez, Dionisio Cagas, Anastacio Jasper, and Celestino Ente.

Poverty incidence of Pilar Source: Philippine Statistics Authority[14][15][16][17][18][19][20][21]