Morganza Spillway emergency use to divert additional water from the Mississippi River into the Morganza floodway, which merges downstream with the Atchafalaya floodway before entering the Gulf. Diversion of water from the Mississippi's main channel has the effect of lowering water level in the Mississippi downstream of the spillway, helping to relieve stress on levees and other flood control structures both upstream and down. Besides controlling flooding in a given event, the system is also designed to prevent the Mississippi River from permanently altering course down the Atchafalaya River, bypassing Baton Rouge and New Orleans. Water that passes the Morganza Spillway first
3rd Missouri Regiment of Colored Infantry Gulf, to September 1864. 2nd Brigade, 1st Division, United States Colored Troops, District of Morganza, Dept. of the Gulf, to February 1865. 1st Brigade, 1st Division, United States Colored Troops, District of Morganza, Dept. of the Gulf, to May 1865. Northern District of Louisiana, Dept. of the Gulf, to July 1865. Moved from Benton Barracks, Missouri, to Port Hudson, Louisiana, arriving March 19, 1864, and duty there till June. Moved to Morganza, Louisiana, and duty there till June 1865. Action at Mt. Pleasant Landing, Louisiana, May 15, 1864 (Detachment). Expedition from Morganza to Bayou Sara September 6–7, 1864. Moved to