The Steele's Bayou expedition was a joint operation of Major General Ulysses S. Grant's Army of the Tennessee and Rear Admiral David D. Porter's Mississippi River Squadron, conducted as a part of the Vicksburg Campaign of the American Civil War. Its aim was to move Union forces from the Mississippi River to a point on the Yazoo River upstream of Confederate Lieutenant General John C. Pemberton's defenses of Vicksburg. To avoid enemy artillery in place on the bluffs to the east of the city, the expedition would leave the Yazoo and proceed indirectly on a route through a series of waterways in the flood plain to the east of the Mississippi. The army and navy contingents of the expedition moved separately, although their movements were coordinated. The naval flotilla moved into Steele's Bayou on March 14, 1863. Two army transports followed them on the opening leg; others were to come later if the route were to prove satisfactory. Traversing Steele's Bayou was not particularly difficult, but the second leg, along Deer Creek, proved impossible. The waterway, narrow and with frequent turns, forced the vessels to move at snail's pace. Exploiting this, the Rebels further impeded progress by felling trees across the stream, and brought the Union force to a halt within of the Rolling Fork. The flotilla would have retreated, but Confederate troops got in their rear on Deer Creek and began felling trees there also. With his vessels effectively trapped, Porter sent an urgent appeal for help to the Army, and then issued orders to his captains to prepare to destroy their ships rather than let them fall into enemy hands. The soldiers, with the personal prodding of Major General William T. Sherman, made a forced march that got to the flotilla on March 22. They easily drove off the Confederate patrols that were blocking the retreat, so Porter and his vessels were able to move back into Steele's Bayou. By March 27, the entire expedition was back on the Mississippi, having accomplished nothing. The Steele's Bayou expedition was Grant's last attempt to attack Pemberton's right flank. Following its failure, he turned his attention to the enemy left flank, and soon began the movement that led to the capture of Vicksburg. Background The campaign to capture the Confederate stronghold at Vicksburg, Mississippi, the last major obstacle to Union control of the Mississippi River, had bogged down in the winter