The Battle of Poison Spring was fought in Ouachita County, Arkansas on April 18, 1864, as part of the Camden Expedition, during the American Civil War. A Union force commanded by Major General Frederick Steele had moved from Little Rock, Arkansas towards Shreveport, Louisiana in support of Major-General Nathaniel Banks' move up the Red River towards Shreveport. After Banks was defeated at the battles of Mansfield and Pleasant Hill, Steele was isolated in Arkansas. Short on supplies, Steele sent a detachment commanded by Colonel James M. Williams to search for supplies. Williams' column was attacked by Confederate troops under the command of Brigadiers General John S. Marmaduke and Samuel B. Maxey. After a sharp fight, Williams' command was routed, losing its wagon train and four cannons. The defeat at Poison Spring and another defeat at the Battle of Marks' Mills a week later led Steele to retreat to Little Rock. The battle is infamous for the Confederates' slaughter and mutilation of African-American Union soldiers of the 1st Kansas Colored Infantry. Poison Springs Battleground State Park, which is part of the Camden Expedition Sites National Historic Landmark, preserves a portion of the site of the battle. Background In late 1863, during the American Civil War, Union leadership was interested in sending an expedition to attack the Confederate state of Texas. Major-General Nathaniel Banks began making preparations for an invasion of Texas via the Gulf of Mexico, but Major-General Henry Halleck, Union general-in-chief, preferred an advance along the Red River. Halleck outranked Banks, so Banks was eventually forced to accept Halleck's attack plan. It was determined that Banks would lead a force along the course of the Red River, while Major General Frederick Steele would move southward through Arkansas to join Banks eventually. The Confederate forces in the region were part of the Trans-Mississippi Department, which was commanded by Lieutenant-General E. Kirby Smith from his headquarters in Shreveport, Louisiana. Banks' advance up the Red River was contested by the forces of Major-General Richard Taylor, one of Smith's subordinates. Taylor attacked and defeated Banks at the Battle of Mansfield on April 8, 1864. The next day, Taylor assaulted Banks' new position during the Battle of Pleasant Hill but was repulsed by the Union army. Despite winning a tactical victory over Taylor at Pleasant Hill, Banks abandoned his campaign and retreated. Banks' retreat left Steele's army in Arkansas on its own. Steele had been