Old River Control Structure such that the volume of the two rivers is split 70%/30%, respectively, as measured at the latitude of Red River Landing. This flow split was not based on science, but rather was based on the approximate flow allocation between the two rivers that existed at the time of construction. Water diverted at Old River flows into the Atchafalaya Basin, first entering the Red River, then continuing down the Atchafalaya River to the Gulf of Mexico, bypassing Baton Rouge and New Orleans (see diagram). The Morganza Floodway, between the Mississippi and the Atchafalaya Basin nearby downstream, is normally closed, but can
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