Numerous stories and beliefs had passed on through the years regarding how Caloocan came to be known by its present name. The following stands out as the most popular from its beginning as a humble barrio of the town of Tondo located in a “libis” (lowland). It came known as “libis Espina” or Aromahan. Another interesting story tells of Caloocan originating either from the tagalong work “look” meaning bay or “sulok” meaning corner. Caloocan might have meant “nasa sulok” look in the corner of Caloocan is located where the ends of the old town of tondo and Tambombong (now Malabon) meet. At the end of the 18th century, the fishermen of Aromahan climbed the hills to open homesteads in Caloocan. Here the land free of thorny plants that (intersected) the banks/shorelines, although the hill was naturally story, some form of agriculture was possible and fishermen became farmers. In 1815, Caloocan was separated from Tondo and became an independent municipality. Its original territory extended to the foothills of Marikina, San Mateo and Montalban in the east, Tinejeros, Tanza and Tala Rivers in the North; San Francisco del Monte, Sampalok, Sta. Cruz and Tondo in the South; and Dagat-Dagatan or Aromahan in the West. Caloocan was part of history, which unfolded during the 1896 Philippine Revolution. The first settlement in Libis Espina, established by oppressed people from Tondo, sought refuge in the thorny shores of Dagat-Dagatan. They climbed the hills for more arable lands only to find out these and titles under the name of Hacienda de Maysilo. Then they fought their landlords for hundred years until Andres Bonifacio led them, the Katipuneros. To that fateful day of August 30, 1896, in Balintawak. The Filipino forces in Caloocan participated actively in Intramuros siege of the Spanish forces in Manila until their surrender to the Americans on August 13, 1898. On January 11, 1899 the people of Caloocan showed resistance by coming to terms with Americans, who were bent on extending their supremacy over the country. When the Americans seized the railroads yards that stood between them and the fleeing Emilio Aguinaldo the men of Caloocan fought the new invaders on February 23, 1899, in a counter attack which, but Gen Antonio Luna’s rift with Aguinaldo’s loyalist could have turned the tide of war in favor of free independent Philippines.
In 1901, under the American regime, Caloocan became one of the towns of the province of Rizal. Due to the consolidation of several municipalities, Novaliches became part of Caloocan pursuant to Act 942, as amended by Act 984 and 1008 of the Philippine Commission. In the same year, pursuant to Commonwealth Act 502, which created Quezon City as Capital of the Philippines, Caloocan lost the following barrios or sitios, namely; Balingasa, Kaingin, Kangkong, La Loma, Malamig, Matalahib, Masambong, San Isidro, San Jose, Santos and Tatalon.In 1949, boundaries of Quezon City were redefined pursuant to Republic Act 392 as recommended by the Capital City Planning Commission. Caloocan again lost several barrios namely; Baesa, Bagbag, Bahay Toro, Banlat, Noalichez, Pasong Tamo, San Bartolome and Talipapa. This explains why the City of Caloocan has two separate territories. Then in 1961, the people of Caloocan turned the historic town in to a city through a plebiscite held in accordance with House Bill 6038, which was passed and approved by both chambers of the defunct Philippine Congress. This led to the signing of RA 3278 declaring Caloocan as a City in Feb. 16, 1962 by the President Diosdado Macapagal.