Initially very few people lived in the town, and most were closely related. Each group had a leader called "tandis". Different groups spoke different languages; Pampango, Pangasinan, Ilocano and Tagalog. From Malolos, the friar curate frequently visited the place, preaching the Catholic faith, using the "balsa" or bamboo raft as his means of transportation. The missionaries decided to clear the land and establish settlements, from which they could work to bring unity to the people. They needed ideas to bring this about, so each "tandis" drew up a plan to pursue. The groups of people labored, so much so that when the priest returned seven years later, he found the area completely cleared. The priests's party inquired among the natives as to whom the credit should go, and the Pampangos exclaimed, "Quing wawa". Thereafter, every now and then, to every question of the friars the people would reply "Quing wa". As a consequence, the place had come to be referred to as Quingua. During the presidency of Manuel L. Quezon, the then "Alcalde", or Town Mayor, of Quinga, Jose J. Mariano, took the initiative of renaming the town. Congressman Pedro Magsalin, a friend of the Alcalde, sponsored the bill changing the name of the town from Quingua to Plaridel. The bill was passed by the Philippine Congress and was approved by the President, and on December 29, 1936 the town was renamed as 'Plaridel', in honor of the great hero of Bulacan, Marcelo H. del Pilar. The celebrations that followed were attended by political luminaries of the time, including Speaker Gil Montilla, Congressman Magsalin, Nicolas Buendia, Eulogio Rodriguez, Elpidio Quirino and Governor José Padilla, Sr.  Notable families from Plaridel include the Vergel de Dios family (originally from Baliuag and that donated the public market of the town), the Castros, Vistans, Sayos, Garcías, and San Diegos. Plaridel is divided into 19 barangays. In 1954, sitio Mayamot in Barrio Banga was changed to Bagong Silang while a sitio in the eastern part of barrio Tabang, called Bagong Silang, was created. In the , the population of Plaridel, Bulacan, was people, with a density of .