Morganza Spillway in 1954, the Morganza Spillway has been opened twice (in 1973 and 2011), and considered for opening during four other major floods of the Lower Mississippi River. On April 17, 1973, in order to lower the water level of the Mississippi River and relieve pressure on the Old River Control Structure, the Corps of Engineers opened 42 of the 125 steel gates of the Morganza Spillway for the first time since its completion, allowing about half of its maximum designed flowrate to pass from the Mississippi into the Atchafalaya Basin. The spillway received minor scouring and slight damage to the
Battery A, 1st Missouri Light Artillery on Jackson, Miss., July 5–10. Siege of Jackson July 10–17. Ordered to New Orleans, La., August 6, then to Carrollton, and duty there until October. Western Louisiana Campaign October 3-November 30. Bayou Cortableaux October 21. Carrion Crow Bayou November 3. At New Iberia until December 17. Moved to New Orleans, then to Madisonville January 7, 1864. Red River Campaign May 2–20. Moved to Alexandria, La., May 2. Attached to Army of the West and Department of the Missouri. Retreat to Morganza May 13–20. Expedition from Morganza to the Atchafalaya River May 30-June 6. Moved to Carrollton June. Duty there and