The first inhabitants of Abra were the ancestors of the Bontocs and the Ifugaos. When they moved to settle in the old Mountain Province, those who were established themselves near Tineg River, thus the name Tingguians or Itneg/Isneg (I-tineg), remained. The Ilocanos came later and occupied the low lands.
In the late 1590s, Augustinian friars penetrated the valley of the Abra River and established a mission in Bangued. In 1598 a Spanish garrison was established there to protect the Ilocanos who converted to Christianity from Tingguian raids. Abra was then named El Abra de Vigan or the 'opening of Vigan'.
During the Silang Revolt of 1762-1763, Abra played a significant role as the last stand of the Ilocano heroine Gabriela Silang. After Gabriela’s husband, Diego Silang, was assassinated, she and her followers retreated in Abra and carried on with her husband’s struggle. In 1763, she was overpowered by a strong Spanish force and was hanged in Vigan together with her trusted lieutenants.
Beginning in the 19th century, missionary activity was resumed in earnest and a number of towns established to preach to the newly settled and Christianized Tinguians.
In 1818 the Ilocos region, including Abra, was divided into Ilocos Norte and Ilocos Sur.
In 1846, Abra was separated from the province of Ilocos Sur and established as a politico-military province. 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.
In 1905, the province of Abra was annexed as a sub-province of Ilocos Sur.
In 1908 the Philippine Commission once again annexed Abra to Ilocos Sur in an attempt to resolve Abra's financial difficulties.
In March 1917, Abra regained its status as a separate province through the passage of Act No. 2683. But on March 9, 1917, the Philippine Assembly re-established Abra as a province.
In 1942, the Japanese forces occupied the Philippines and entered Abra.
In 1945, the liberation in Abra in Northern Luzon from defenders by the Allied Philippine Commonwealth forces and the local Cordilleran guerrillas against the Japanese during the Battle of Abra at the end the Second World War.
In 1972, Abra remained part of the Ilocos Region.
The rebellion peaked in 1985, after which, it dissipated when the Cordillera People’s Liberation Army broke away from the communist movement and championed the effort to establish an autonomous Cordilleran government.
The revolutionary priest, Father 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.
In 1987, Abra, through E. O. 220, Abra became a part of the Cordillera Administrative Region.