SAMUEL G. COSGROVE was born in Tuscarawas County, Ohio. After serving as an infantryman in the Civil War, he received M.A. and LL.B. degrees from Ohio Wesleyan University and was a teacher and principal of a Cleveland high school. He moved to the Nevada mining district and then on to Pomeroy, Washington Territory in 1882, where he was president of the Pomeroy School Board for eight years and the city's mayor for five terms. He was a candidate for the Republican gubernatorial nomination at several state conventions before filing for nomination in the first primary after adoption of a direct primary law. When no candidate won the majority of votes, the votes for second-choice candidates were added and Cosgrove won the nomination accordingly. He went on to win election, but suffered a heart attack shortly thereafter. Too weak to complete his address during his inaugural ceremony, he was granted a leave of absence. He went to Paso Robles, California to recuperate but died there two months later. His body was returned to Olympia and laid in the Capitol rotunda, and he was buried in the Masonic Cemetery in Olympia.
Official Records at Washington State Archives, 1 document, request for leave of absence (1/27/1909).
List of finding aids available at the Division of Archives and Records Management, Office of the Secretary of State. Available in hard copy: Guide to the Papers of the Governors of Washington, Volume 2: 1889-1919—Governor Ferry through Governor Lister.
The National Cyclopaedia of American Biography, Vol. 14 (Supp.). 'New York: James T. White & Company.
Sobel, Robert, and John Raimo, eds. Biographical Directory of the Governors of the ''United States, 1789-1978, Vol. 4. Westport, CT: Meckler Books, 1978. 4 vols.