In May of 1869 he graduated from the Military Academy with the rank of ensign of cavalry and entered the Chilean Army, forming part of the Regiment Mounted Hunters. As an officer of that cavalry regiment he participated in the military campaigns of the Occupation of Araucanía, between 1872 and 1874. He operated on the Malleco River line, under the command of Colonel Gregorio Urrutia. During this period he was promoted to second lieutenant and then lieutenant in 1875.