Original works of art

Hays studied with John Rubens Smith. He was a naturalist as well as a painter, and his subjects were chiefly animals; his best-known work was done in the West, particularly on a journey on the Missouri River in 1860. He also went to Nova Scotia, the Adirondacks and England; he spent most of his life, however in New York. His son by the same name was also an artist.

He was a member of the National Academy of Design. He exhibited there, showing Head of a Bull-Dog in 1852, The Gathering of Herds in 1866 and American Elk in 1874, among other works. He also exhibited at the Pennsylvania Academy of the Fine Arts, where he showed The Rabbit Hunt in 1857, And The Esquimax Dog in 1863 and American Elk in 1868, and at the American Art-Union. The New York Historical Society has several of his works, among them Terrier's Head, and Spaniel and Terrier. The Glen Bow Museum in Calgary, Alberta, Canada has his Study of a Pronghorn, the Gilcrease Institute in Tulsa, OK has his Buffalo Herd on the Move and his Prairie Dog Village is at the Tweed Museum at the University of Minnesota in Duluth. Other institutions holding his work include Corcoran Gallery in Washington, DC, the Denver Art Museum, the New York Public Library, the City Art Museum in St. Louis, Washington University and the Amon Carter Museum in Forth Worth, TX.