On April 6, 1862 the Confederate Army of Mississippi commanded by General Albert Sidney Johnston attacked the Union Army of the Tennessee under the command of Maj. Gen. Ulysses Grant at Pittsburgh Landing.  By evening Johnston’s forces had pushed the Union line back to the banks of the Tennessee River.  That night the Union Army of the Ohio commanded by Maj. Gen. Don Carlos Buell arrived to reinforce Grant’s army.  The following morning, successful counter attacks of Grant and Buell forced the Army of Mississippi to withdraw and retreat to Corinth, Mississippi.  With the defeat at Shiloh, Confederate control of the upper Mississippi Valley was significantly diminished and placed the Union army in a strategic position to capture key objectives in the south.