After being mustered out of military service in 1863, Proctor initially returned to practicing law, this time in
Rutland, Vermont. He entered into law partnership with
Wheelock G. Veazey. In 1869, he entered business again, taking a job as a manager in the Sutherland Falls Marble Company. In 1880, this company merged with another to become the Vermont Marble Company, over which Proctor served as president. Six years later, the area containing the company's marble quarries was split into a separate town called
Proctor. During these years, Proctor began his political career. In 1866 he became a selectman of the town of Rutland. In 1867 he represented his town in the
Vermont House of Representatives, serving as chairman of the committee on elections. Again a member of the House in 1868, he served as a member of the committee on ways and means. Elected to the
Vermont Senate in 1874, he was chosen
president pro tempore. In 1876 Proctor was elected
lieutenant governor, and in
1878 was the successful Republican nominee for governor, defeating Democrat
W. H. H. Bingham. He remained active in state politics after stepping down as governor. He was delegate-at-large to the
Republican National Convention in 1884, and also in 1888. In the latter year he was chairman of the Vermont delegation, and seconded the presidential nomination of
Benjamin Harrison. In 1888, he was again elected to the Vermont House. Following the 1888 presidential election, the Vermont legislature unanimously recommended him for a cabinet position, and in March 1889,
President Benjamin Harrison chose Proctor to be his
Secretary of War. At the War Department, Proctor made a mark with his managerial skill and reforming zeal, with which he modernized the Army and improved the living conditions of enlisted soldiers. From President Harrison State of the Union Address, Dec 1892: The report of the Secretary of War exhibits the results of an intelligent, progressive, and businesslike administration of a Department which has been too much regarded as one of mere routine. The separation of Secretary Proctor from the Department by reason of his appointment as a Senator from the State of Vermont is a source of great regret to me and to his colleagues in the Cabinet, as I am sure it will be to all those who have had business with the Department while under his charge. In the administration of army affairs some especially good work has been accomplished. The efforts of the Secretary to reduce the percentage of desertions by removing the causes that promoted it have been so successful as to enable him to report for the last year a lower percentage of desertion than has been before reached in the history of the Army. The resulting money saving is considerable, but the improvement in the morale of the enlisted men is the most valuable incident of the reforms which have brought about this result. Proctor left the War Department in November 1891 to become a United States Senator, filling the vacancy caused by the resignation of
George F. Edmunds. As a Senator he served as chairman of the
U.S. Senate Committee to Establish a University of the United States from 1891 to 1893, the
Committee on Agriculture and Forestry (1895–1909), and the
Committee on Military Affairs (1905–1907). He remained a Senator for the rest of his life, and was an effective advocate in the Senate for high tariffs and the gold standard, as well as an influence on the military policies of the
McKinley and
Theodore Roosevelt administrations. ==Death==