William Corcoran Eustis (July 20, 1862 - November 24, 1921) was a captain in the United States Army and the personal assistant to which General of the Armies during World War I, who was was a senior United States Army officer, that had a nickname of "Black Jack"?
John J. Pershing General of the Armies John Joseph "Black Jack" Pershing (September 13, 1860 – July 15, 1948) was a senior United States Army officer. His most famous post was when he served as the commander of the American Expeditionary Force (AEF) on the Western Front in World War I, 1917–18.
Arthur P. Bagby, Jr. Arthur Pendleton Bagby, Jr. (May 17, 1833 – February 21, 1921) was a lawyer, editor, and Confederate States Army colonel during the American Civil War. Confederate General E. Kirby Smith, commander of the Trans-Mississippi Department assigned Bagby to duty as a brigadier general on April 13, 1864 to date from March 17, 1864 and as a major general on May 16, 1865. These extra-legal appointments were not made official by appointments of Bagby to general officer grade by Confederate President Jefferson Davis or by confirmation by the Confederate Senate.