He graduated from Yale College in 1844, where he was a member of Skull & Bones; was employed as a store clerk 1844-1847; engaged in manufacturing pursuits in Erving, Franklin County, Mass., 1847-1857; became a member of the Massachusetts state senate 1850; a member of the Massachusetts state house of representatives 1853-1855; moved to Greenfield in 1858 and engaged in banking; elected as a Republican to the Thirty-eighth and to the four succeeding Congresses and served from March 4, 1863 to December 5, 1871, when then he resigned, having been elected Governor of Massachusetts.

He was chairman, Committee on Claims (Forty-first Congress); Governor of Massachusetts 1872-1874, when he resigned, having been elected as a US Senator; elected as a Republican to the United States Senate to fill the vacancy caused by the death of Charles Sumner and served from April 17, 1874 to March 3, 1875; he was not a candidate for reelection.

He was president of the Greenfield National Bank; he was a trustee of Yale College, the Massachusetts Agricultural College, and Smith College, of which he was also a benefactor, and a member of the board of overseers of Amherst College from 1864-77. Harvard University conferred the degree of EL. D. upon him in 1872.

He was also a member of the American board of the American Home Missionary Society, and the American Missionary Association Residuary legatees, leaving to each society about $50,000 in his will. He was also a benefactor of the Greenfield Public Library. He died in Springfield, Hampden County, Mass., on October 5, 1887 while attending a session of the American Board of Commissioners for Foreign Missions (ABCFM), which he was also a member ; a director of the Connecticut River Railroad.

Preceded by: Amasa Walker Member of the U.S. House of Representatives from Massachusetts's 9th congressional district March 4, 1863 - December 5, 1871 Succeeded by: Alvah Crocker Preceded by: William Claflin Governor of Massachusetts January 4, 1872 - April 29, 1874 Succeeded by: Thomas Talbot Preceded by: Charles Sumner U.S. Senator (Class 1) from Massachusetts April 17, 1874 to March 3, 1875 Served alongside: George S. Boutwell Succeeded by: Henry L. Dawes Governors of Massachusetts  Colony  Endicott • Winthrop • T. Dudley • Haynes • Vane • Winthrop • T. Dudley • Bellingham • Winthrop • Endicott • T. Dudley • Winthrop • Endicott • T. Dudley • Endicott • Bellingham • Endicott • Bellingham • Leverett • Bradstreet

 Dominion  J. Dudley • Andros • Bradstreet

 Province  W. Phips • Stoughton • Coote • Stoughton • Governor's Council • J. Dudley • Tailer • Shute • Dummer • Burnet • Dummer • Tailer • Belcher • Shirley • S. Phips • Shirley • S. Phips • Pownall • Hutchinson • Bernard • Hutchinson • Gage