More about December 5th. . . Frontier Army Museum Fort Leavenworth Explains Fort Leavenworth‘s role in the exploration and expansion of the western United States. Bird’s eye view of Fort Leavenworth, Kansas Black and white (brown) lithograph of Fort Leavenworth. Henry Leavenworth Henry Leavenworth portrait by George Catlin. Missouri Historical Topographic Maps With dates of last survey.