Fort Jackson engineering sketches, 1841-1858, 51 items. Location: OS:F. Fort Jackson is an historic fort located 40 miles from the mouth of the Mississippi River in Plaquemines Parish, Louisiana. Engineering sketches of Fort Jackson in Plaquemines Parish, which were sent to Major P. G. T. Beauregard in 1858.  Sketch (1856) shows the shoreline of the Mississippi River near the fort drawn under the direction of Major Beauregard. Although the sketches predate the Civil War, the fort played a significant role during the war. Mss. 1343.