In the revolution of 1852, Mitre entered the service of the National Guard, and this movement being successful he was appointed to a cabinet position, the first political office he had held in his own country. This government did not last long, and Mitre was soon found in the military service again. For a while he edited _El Nacional_, and took a part in the forming of a new constitution. For a number of years his time was alternated between military service, literary work, editorial services and political office. In 1860 he was elected governor of the province of Buenos Aires, and in 1862, by the victory of Pavon, General Mitre succeeded to the presidency of the republic. The accession of this high-minded patriot ended the period of uncertainty in Argentina. Although he reached his high position as the representative of victorious Buenos Aires, he immediately set himself to work to remodel and strengthen the federation, a task for which he had long prepared himself. Buenos Aires became the seat of government once more. The autonomy of the provinces was not interfered with, but power and population naturally gravitated toward that city. From that time the tendency has constantly been toward strengthening the bonds of cohesion. President Mitre also sought to work out a more democratic form of government, as preventative of the uprisings which were so numerous and distracting. This work, however, was seriously interrupted by the Paraguayan war, in which he acted as Commander-General of the allied forces from 1865 to 1868. The aggressive and ambitious policy of General Lopez, the dictator of that country, united Brazil, Uruguay and Argentina in an attempt to throttle his pretensions. It was only accomplished after a bloody war of several years, and the killing or disabling of almost every man in Paraguay capable of bearing arms. In 1868 President Mitre’s term of office ended, and he was presented by the people with a fine home in the capital. After his retirement he served as senator for that province, in which he did good service for his country. He did effective work as editor of _La Nacion_, a journal which he owned, and through which he propounded his political ideas. At last ripe in years, full of honours and with the universal appreciation of his fellow countrymen he departed from this life in 1906.