He was born in Marietta, Ohio to merchant Benjamin Ives Gilman and Hannah Gilman. Benjamin Ives Gilman, born in 1766, was a native of Exeter, New Hampshire, where his ancestors were among the most prominent early settlers and where he graduated in the first class of the Phillips Exeter Academy. In 1837 Winthrop Sargent Gilman let the abolitionist Elijah Parish Lovejoy hide his printing press in one of Gilman's warehouses in Alton, Illinois. In the ensuing riot the angry mob burned Gilman's warehouse to the ground and killed Lovejoy. Following the Alton riots, Gilman moved to New York City and entered the family banking business. He was married to Abia Swift Lippincott Gilman, who in 1900 narrowly escaped burning to death from a gasoline torch in front of the Charles Scribner mansion at 12 East Thirty-eighth Street. Winthrop Gilman had an abiding interest in science and built a private observatory at his home 'Fern Lodge' at the Palisades, New York, where he frequently observed meteors. Gilman, Son & Co. in New York often acted in conjunction with the interests of the Brown family of Providence, Rhode Island, founders of Brown University. Subsequently, John Nicholas Brown and the Gilman Land Company, an offshoot of the Gilman family banking business, were involved in the development of the Gilman Block in Sioux City, Iowa, as well as other real estate properties. Winthrop Sargent Gilman's sons were Winthrop S. Gilman, Jr., Benjamin Ives Gilman, Theodore Gilman and Arthur Gilman. Arthur was a banker with the family firm, but when his health faltered, he retired to his estate 'Glynllyn' in the Berkshires near Lee, Massachusetts, and became a writer on historical subjects and family history, a philanthropist and the founder of Radcliffe College in Cambridge, Massachusetts.
Papers
Papers of Winthrop Sargent Gilman and his sons and other Gilman family members are available for research use at the Minnesota Historical Society. They include correspondence, diaries, newspaper clippings, scrapbooks, printed materials, and genealogical information.