Herman Hattaway and Eric B. Fair, "Hitchcock, Ethan Allen," American National Biography Online, February 2000, http://www.anb.org/articles/04/04-00506.html.
Although Hitchcock's antiwar conviction mellowed somewhat during the Mexico City campaign, he remained aloof from the typical pleasures and pastimes of army life. In his journal he wrote, "I find so little to interest me in the military profession that I had rather study or read books of philosophy. I fear I am not in my proper vocation." Following the Mexican War, Hitchcock was appointed as commander of the Military Division of the Pacific, where he was instrumental in forcing the arrest of William Walker, an American adventurer who had attempted to establish an independent republic in Baja California. Hitchcock ordered the seizure of Walker's brig, Arrow, an act that reportedly angered Secretary of War Jefferson Davis. In 1855--perhaps spitefully--Davis refused Hitchcock's request for a leave of absence due to ill health; Hitchcock reacted by submitting his resignation from the army on 18 October 1855.