George Marcellus Ransom was born in Springfield, New York, on June 18, 1820, the son of Warren Greene Ransom and Sarah Tilden. Ransom joined the United States Navy in 1839 and served on the Marion and Erie before attending the Philadelphia Naval School, where he was promoted to midshipman in July 1845. Ransom was stationed at the Naval Observatory in Washington, D.C., and on different ships along the coasts of Africa and Brazil, on the Great Lakes, and in the Pacific, throughout the remainder of the 1840s and the 1850s. During the Civil war, he commanded the Kineo and, after his promotion to commander in June 1863, the Mercedita , Grand Gulf , and Muscoota . He participated in engagements in Louisiana in 1862 and helped capture Atlantic blockade runners in the later years of the war. He commanded navy vessels in the North Atlantic Squadron until March 1877, when he was promoted to commodore. Ransom was forced to retire from the navy in 1882 on account of old age. He lived in Norwich, Connecticut, until his death on September 10, 1889. Ransom and his wife, Jane S. Manley, married on June 25, 1845, and had six children: Grace, Manley, William, Chassie, Marcia, and Farragut.