Floods in the United States: 2001–present floodgates of the Morganza Spillway were opened, marking the first use of the gates since the 1973 flood. 330 of the Bonnet Carré Spillway's gates were opened to save the levees protecting New Orleans. There was concern that if the Old River Control Structure, the Morganza Spillway, or the Bonnet Carré Spillway failed, the Mississippi River could change its course, flowing either into the Atchafalaya Basin or Lake Pontchartrain. In early September, the remnants of Tropical Storm Lee had stalled due to Hurricane Katia. As a result, the main cyclone stalled over the Midwest, and a cold front associated with
6th Missouri Volunteer Cavalry May 18-July 4. Assaults on Vicksburg May 19 and 22. Mason's Ford. Big Black River, June 9. Advance on Jackson, Miss., July 4–10. Near Baker's Creek July 7. Bolton's Station July 8 (detachment). Near Clinton July 8 (detachment). Near Jackson and near Clinton July 9 (detachment). Siege of Jackson July 10–17. Brookhaven July 18 (detachment). Near Morganza, La., September 8. Atchafalaya September 8–9. Hornersville, Mo., September 20 (2nd Battalion). Sterling's Farm, on Bayou Fordoche, near Morganza, September 27. Western Louisiana Campaign October 3-November 30. Reconnaissance toward Opelousas October 20. Opelousas, Barre Landing, October 21. Washington October 24. Bayou Bourbeaux November