On July 4, 1863, the Confederate garrison at Vicksburg, Mississippi, marched out of their fortifications and stacked their arms. Thirty-one thousand soldiers surrendered. The Confederacy was cut in two.

The Gibraltar of the West

Vicksburg sat on 200-foot bluffs above a hairpin bend in the Mississippi River. Confederate artillery commanded the channel. No Union vessel could safely pass. As long as the Confederacy held Vicksburg, it held the river — and the river was the artery connecting the eastern and western halves of the rebellion, including the supply lines from Texas and Louisiana.

Lincoln called Vicksburg the key. He was right.

Grant's Audacity

Ulysses Grant's campaign to take Vicksburg was among the most operationally daring of the war. After months of failed approaches — canal-digging schemes, bayou routes, direct assaults — Grant made a decision that violated every conventional military principle: he cut loose from his supply line, marched his army down the west bank of the Mississippi below the city, ran gunboats past the Vicksburg batteries at night, crossed to the east bank, and drove deep into Mississippi.

In 17 days, he fought five battles, covered 180 miles, and captured the state capital at Jackson before turning back to besiege Vicksburg from the land side. His army subsisted largely off the countryside. He had no supply line to protect.

The Siege

The assault on May 22, 1863, failed. The Confederate fortifications were too strong, and Grant settled in for a siege. For 47 days, Union artillery pounded the city while Confederate defenders and Vicksburg's civilians dug caves into the hillsides for shelter. Food ran out. Soldiers ate mule meat. Citizens ate rats.

When Confederate commander John Pemberton finally surrendered on July 4 — choosing the date deliberately, believing Grant might offer lenient terms in honor of Independence Day — the Mississippi River was open from Minnesota to the Gulf. The Confederacy's western frontier collapsed. Texas beef and Louisiana salt would never again flow east in significant quantities.

The same day, Lee began his retreat from Gettysburg. Pemberton's surrender, combined with the repulse in Pennsylvania, marked the effective peak of Confederate military power.

Grant's star was now irreversibly in the ascent. Lincoln said he wished he knew what Grant drank, so he could send a barrel to his other generals.