The first inhabitants of Abra were the ancestors of the Bontocs and the Ifugaos. These inhabitants eventually left to settle in the old Mountain Province. Other early inhabitants were the Tingguians, or Itnegs, as they are also known.
In 1598, a Spanish garrison was established in Bangued to protect Christian Ilocanos from Tingguian raids. Originally the area was called El Abra de Vigan ("The Opening of Vigan"). During the British Occupation of the Philippines, Gabriela Silang and her army fled to Abra from Ilocos and continued the revolt begun by her slain husband, Diego Silang. She was captured and hanged by the Spanish in 1763.
In 1818, the Ilocos region, including Abra, was divided into Ilocos Norte and Ilocos Sur. In 1846, Abra was created as a political-military province with Lepanto as a sub-province. It remained so until the arrival of the Americans in 1899.
The revolutionary Marxist priest, Conrado Balweg, who fought for the rights of the Cordillera tribes, began his crusade in Abra. After successfully negotiating a peace accord with Balweg's group in 1987, the Philippine government created the Cordillera Administrative Region, which includes Abra.
Abra is hemmed in by the towering mountain ranges of the Ilocos in the west and the Cordillera Central in the east. The Abra River runs from the south in Benguet to the west and central areas, bisecting the whole Abra Valley. It is joined by the Tineg River originating from the eastern uplands at a point near the municipality of Dolores.
Abra's inhabitants are mostly descendants of Ilocano settlers and members of the Tingguian tribe. As of 2011, the population of the province is 240,141.
The predominant languages are Ilocano and Itneg. Based on the 2000 census survey, the majority of the province population is Ilocano 71.9%. Other ethnic groups living in the province are the Tinguian 18.7%, Ibanag 4.5%, Isneg 3.2% and Tagalog 0.4%.
In 1992, the natural dye industry, together with loomweaving and embroidery, was revived by former Governor Ma. Zita Claustro-Valera, the first female governor of Abra.
Abra's economy is agriculture-based. Its major crops are rice, corn, and root crops; commercial products include coffee, tobacco, and coconut. Extensive grassland and pasture areas are used for livestock production.