Del Valle studied in the Faculty of Law of the University of Buenos Aires. He abandoned his studies to join the army during the War of the Triple Alliance, took them up later and graduated. As a young man he worked in the El Nacional newspaper of the city of Buenos Aires.
He entered politics supporting Adolfo Alsina, and was elected diputado (member of the Argentine Chamber of Deputies) in 1870. In 1876 he was elected national senator, and presided the Upper House since 1880.
He took part in the activism against the government of Miguel Juárez Celman in 1890, and was even considered an instigator of the uprisings of the 1890 revolution, due to which he was forced to leave his senatorial office, but he was re-elected the next year. From that point on, he supported the formation of the Radical Civic Union, an offshoot of the Civic Union proposed by Leandro Alem.
Del Valle also served in several Ministries during the term of President Luis Sáenz Peña (1892–1895), and after his retirement he taught law in the University of Buenos Aires. He died in his office at the Faculty of Law in 1896.