Stories have been told by old folks of this barangay that hunters from the lowlands who hunt in the forested nearby mountains usually roast and clean their hunted wild animals at one of the creeks (now called Polpog Creek). Hunters were already used to rest along this creek and roast some meat for their meals. Thus, this creek was called “polpog” which means “to roast”. Whatever meat they could not cook, and in order to preserve the meat, they let these dry under the sun, in Iloko, “Idalangdang”.  The village people then used to call the place “Dalangdang” because of the common practice of hunters in drying their hunted meat and the savorous smell of “dalangdang” in the area. Years passed and the world “dalangdang” was modified and pronounced as “Dalacdac”.

           Dalacdac was then a sitio of Barrio Caoayan until it was separated as a regular barrio in 1968 by virtue of Provincial Board Resolution No. 531.  One of the clamors for its separation from Caoayan was that barangay funds allocated by the government for a barangay was not enough for development projects for a wide Caoayan.

           Upon creation as a barangay, the late Regulo Apilado, a well-known elder and leader in the community was chosen to head the first set of Barangay Council.  He held the reign for 14 year (1968-1982).  As a regular barangay, developments started to be introduced.

           It is bounded on the east by Barangays Upper Tumpoc and New Poblacion; west by Barangay Caoayan; south by Lower Tumapoc and north by Old Poblacion.  It has two sitios namely; Polpog, at the north eastern part, and Gabur, at the south eastern part. The climate is temperately hot.

           The center of the barangay is 1.010 kilometers from the national highway; and it could be reached by foot in about 15 minutes.  The inhabitants are predominantly Ilocanos.  Since the community is an agricultural area, most of the residents are farmers.

           Lower Tumapoc-Dalacdac River and Polpog Creek flow along the barangay where residents could get rich marine/aquatic resources.

           It has an area of 119.0989 hectares with a total population of 3018 (in 2015).

           There are two potential Tourism destinations in the barangay; the Dalacdac Mini Dam and the Sunpeak Resort.