The key to control the Mississippi River captured by General US Grant on July 4, 1863, was the city of Vicksburg, Mississippi. Vicksburg was a strategic city located on a high bluff overlooking the Mississippi River. It was a major Confederate stronghold and a vital supply point for the Confederate Army in the West. Grant's capture of Vicksburg split the Confederacy in two and gave the Union control of the Mississippi River, a major artery of transportation and commerce. This was a major turning point in the Civil War and helped to pave the way for the Union victory.