Richard Lowe, Walker’s Texas Division C.S.A.: Greyhounds of the Trans-Mississippi (Baton Rouge: Louisiana State University Press, 2004), 61.
[John George] Walker enlisted in the U.S. Army during the Mexican War and fought with Gen. Winfield Scott’s army from Vera Cruz to Mexico City, receiving a wound at Molino del Rey and a brevet rank of captain for gallant service. After the war he was promoted to captain and served at various army posts in Oregon, California, New Mexico, and Texas. Between assignments, he made a grand tour of Europe, visiting the great capitals of London, Paris, and Rome, at least part of the time with Sen. Stephen A. Douglas of Illinois. In short, on the eve of the Civil War, Walker was well equipped to lead. His prominent family had prepared him for great things; he was well educated and highly experienced and accomplished in his chosen field; and his travels across the United States, Mexico, and Europe had given him an unusually wide perspective on public affairs.