Born in Brownsville, Pennsylvania, Townsend attended the common schools of Pittsburgh, Pennsylvania, and clerked in a store in Pittsburgh.
He moved to Mansfield, Ohio, in 1839 and engaged in mercantile pursuits. He served as United States marshal during the Kansas troubles. He moved to Cleveland, Ohio, in 1858 and engaged in the wholesale grocery business.
Townsend was elected as a Republican to the Forty-fifth, Forty-sixth, and Forty-seventh Congresses (March 4, 1877 – March 3, 1883).
He served as chairman of the Committee on Railways and Canals (Forty-seventh Congress). He declined renomination.
He died while on a visit to Saint Augustine, Florida, March 17, 1895. He was interred in Lake View Cemetery, Cleveland, Ohio.
He served as member of the Cleveland City Council 1866-1876, serving as president for seven years. He served as member of the State constitutional convention in 1873. He served as member of a wholesale foodpacking firm.