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.
Gustavus Woodson Smith Gustavus Woodson Smith (November 30, 1821 – June 24, 1896), more commonly known as G.W. Smith, was a career United States Army officer who fought in the Mexican-American War, a civil engineer, and a major general in the Confederate States Army during the American Civil War. He briefly commanded the Army of Northern Virginia from May 31 until June 1, 1862, following the wounding of General Joseph E. Johnston at the Battle of Seven Pines, and before General Robert E. Lee took command. Smith later served as Interim Confederate Secretary of War and in the Georgia state militia.