Justin Morgan Had a Horse is a children's historical novel by Marguerite Henry, illustrated by Wesley Dennis and published by Wilcox & Follett of Chicago in 1945. It concerns horse-breeding in Vermont in the late eighteenth century. It was one runner-up for the Newbery Medal in 1946 (a Newbery Honor Book in later terms). An edition was published by Rand McNally in 1954 with new copyrights by both Henry and Dennis. The Library of Congress catalog records report 89 pp. and 169 pp. respectively.