William H. Coats (b. 1841) was the son of Russel B. and Abby Coats of North Stonington, Connecticut. He had at least one sister, Mary. Coats studied at the Connecticut Literary Institution until at least 1859 and moved to Binghamton, New York, in 1863, where he worked in a store owned by the Hines family. He later moved to East Saginaw, Michigan, where he married Alice Little in 1868. Their children were Minnie (1870-1930), Phillip (1874-1902), and Helen.
From the guide to the William H. Coats papers, Coats, William H. papers, 1859-1874, 1860-1868, (William L. Clements Library, University of Michigan)