William Henry Hay was born in Drifton, Florida on July 16, 1860. His father, Turner Hay, was an Army veteran of the Seminole Wars, and served in Harney's Dragoons. Turner Hay also served in the Confederate States Army during the American Civil War, and took part in the battles at Olustee and Natural Bridge. William Hay graduated from the United States Military Academy in 1886, and was a classmate of John J. Pershing. Hay was 22 years old when admitted to West Point, older than all his classmates by several years. As a result, his fellow cadets referred to him as "Dad," the nickname by which he continued to be known.
During the Spanish–American War Hay was a temporary Captain in the United States Volunteers and detailed to the Quartermaster service. He spent four years in Cuba as Collector of Customs at Matanzas and deputy to Tasker Bliss, who was the head of the Cuban Customs Service. Hay was fluent in Spanish, both spoken and written, which enabled him to effectively reorganize and administer the wharves, warehouses, and offices under his jurisdiction.
At the start of World War I Hay was promoted to temporary Brigadier General as commander of the 184th Infantry Brigade, a subordinate command of the 92nd Division, an organization of African-American soldiers and white officers. He led the brigade during combat in France, including combat in the Saint-Dié-des-Vosges area and the Meuse-Argonne Offensive. As was the case with the 93rd Division, the 92nd fought primarily in French sectors, since American and British senior commanders did not want these segregated units fighting in proximity to organizations composed of white soldiers. Despite his success at leading black troops in combat, Hay supposedly expressed a low opinion of African-American soldiers, and argued against allowing them to attend officer training or serve in leadership roles. In contrast, Emmett Jay Scott wrote in 1919 of Hay's praise for African-American soldiers during a ceremony shortly before they returned to the United States: "I have been with colored troops for 25 years, and I have never seen better soldiers than the drafted men who composed this division." On October 26, 1918 Hay was promoted to temporary Major General and assigned to command of the 28th Division after Charles H. Muir was elevated to command of IV Corps. He continued to command the division until the end of the war in November, and remained in command until Muir again assumed command and the division returned to the United States in April, 1919. From April to June, 1919 Hay commanded the Intermediate Section of the Army's Services of Supply, afterwards returning to the United States.
Post-World War I
From June, 1919 to July, 1920 Hay was commander of Camp Custer, Michigan. In July, 1920 he reverted to his permanent rank of Colonel and was assigned as Inspector General of the American Forces in Germany, with headquarters at Koblenz. In May, 1921 he was assigned as chief of staff of the American Forces in Germany, where he remained until his 1922 promotion to permanent Brigadier General and command of the 1st Cavalry Brigade at Camp Harry J. Jones, near Douglas, Arizona. In 1922 his wife and he sustained injuries in an automobile accident, which led to his retirement from the military in 1924. After a year convalescing from his injuries, from 1926 to 1939 Hay was Superintendent of Camp Smith, the New York National Guard's training site. In 1930 his two-star rank was restored when Congress passed legislation allowing general officers from World War I to retire at the highest they had held.
