With the fall of Vicksburg and Port Hudson in July, 1863, the Mississippi River was entirely controlled by the Union. Lincoln and his staff decided that Texas would be the next objective in the trans-Mississippi area. The Red River was chosen as the best approach into Texas and a Navy-Army advance was planned with the Army (35,800 troops) under the command of General N. P. Banks and the Navy commanded by Flag Officer D. D. Porter.
The Union surmised that a successful Red River campaign would accomplish several important goals: it would lead to the confiscation of cotton for New England mills and to the destruction of Confederate supply plants; it would prevent the French-Mexican force and supplies from joining with the Confederates; it would provide protection for the loyal Union population in Texas; and it would bring Texas back into the Union as a voting state.
Following the course of the Red River, the Union Army and Navy
progressed with little opposition through Alexandria and reached Natchitoches by early
April, 1864. At Natchitoches the Army veered away from the Red River, going toward
Shreveport by way of Mansfield, which left them without the support of the Navy. This and
other tactical blunders on the part of General Banks and a series of successful maneuvers
by General Richard Taylor (son of President Zachary Taylor), who commanded the Confederate
forces, were decisive factors leading to the final outcome of the battle.
Like many important battles, the Mansfield-Pleasant Hill engagement was actually a series of encounters taking place over several days. After a two hour cavalry fight with Union forces near Wilson's Farm on April 7, 1864, General Taylor selected to defend a site about four miles south of Mansfield, now the location of the state commemorative area. General Banks did not expect the Confederates to fight until he reached Shreveport and the Union Army became strung out along the narrow road leading to Mansfield. This allowed Taylor to deal with his opponents on more equal terms since the Confederate troops were heavily outnumbered.
At 2:00 P.M. on April 8 the head of the disorganized Union Army (5,700 troops) was confronted by the Confederate Army (8,800 troops) in battle formation. The Union Troops quickly formed a line of battle along a rail fence and a ridge known as Honeycutt Hill. On orders from Taylor, General Alfred Mouton's Division charged the rail fence. Mouton was killed leading the attack, but French born General J. C. Polignac continued the charge and overwhelmed the Union line.
A fresh unit of 1,200 Union Troops formed another line of battle about a mile south of the first. After a brief encounter, Taylor and the Confederates routed the Union forces, taking many prisoners and seizing guns, small arms and wagons abandoned by the fleeing soldiers.
Two miles south of the second line, another 6,000 Union Troops formed a defensive position at Chapman's Bayou, holding this location until dark. During the night the defeated Union forces fell back to Pleasant Hill. On April 9 the fierce Battle of Pleasant Hill was fought with both sides taking heavy losses and withdrawing from the field after dark.
The Union Army rejoined the Navy in Natchitoches and began a long retreat down the Red River. The river had dropped to an unusually low level and the Navy was trapped by a series of rapids near Alexandria. Union Engineer Joseph Bailey solved the problem by having wing-dams built in the river to raise the water level. The Navy finally floated free and the combined Union forces left Alexandria. Confederates opposed the Union retreat at Mansura and then at Yellow Bayou.
On May 18, 1864, the Union forces crossed the Atchafalaya River, ending the disastrous Red River campaign. By turning back these large Union forces, the Confederates were able to prevent complete Union control of Louisiana and to stop progression of the war into Texas.