[1][2] At a very young age he joined the Army of the Andes, along with his older brother, Lieutenant Pedro Pascacio Albarracín, but he was not involved in the campaign in Chile.

Albarracín was ordered by Paz to Córdoba Province, where he fought on the Unitarian side in the battles of San Roque, La Tablada and Oncativo.

[3] He went on to Mendoza Province, where he defeated the Federalist forces that remained after Governor Juan Rege Corvalán fled, fighting two small engagements in La Estacada and beside the Río Tunuyán.

After Facundo Quiroga invaded Cuyo, he came under the orders of General Gregorio Aráoz de Lamadrid in Tucumán Province, and participated in the Battle of La Ciudadela, where the Unitarian League of the Interion was finally defeated.

Albarracín returned to Buenos Aires in 1852, shortly after the Battle of Caseros, and went to San Juan, where he organized a revolt against the caudillo Nazario Benavídez in that year.

Albarracín was released and given command of the provincial army in January 1862 when the province was invaded by troops from Buenos Aires, led by Domingo Faustino Sarmiento (his second cousin), who was elected governor.