When the Spanish–American War broke out, Young was promoted to the temporary rank of major of Volunteers on May 14, 1898. He commanded the 9th Ohio Infantry Regiment which was, in the terminology of the day, a "colored" (i.e. African-American) unit. Despite its name, the 9th Ohio was only battalion sized with four companies. The short war ended before Young and his men could be sent overseas. Young's command of this unit is significant because it was probably the first time in history an African-American commanded a sizable unit of the United States Army and one of the very few instances prior to the late 20th Century. He was mustered out of the volunteers on January 28, 1899, and reverted to his regular army rank of first lieutenant. He was promoted to captain in the 9th Cavalry Regiment on February 2, 1901.