The Vicksburg campaign was one of the Union’s most successful of the war. Although Grant's first attempt to take the city failed in the winter of 1862-63, he renewed his efforts in the spring. Admiral David Porter had run his flotilla past the Vicksburg defenses in early May as Grant marched his army down the west bank of the river opposite Vicksburg, crossed back to Mississippi, and drove toward Jackson. After defeating a Confederate force near Jackson, Grant turned back to Vicksburg. On May 16, he defeated a force under John C. Pemberton at Champion Hill. Pemberton retreated back to Vicksburg, and Grant sealed the city by the end of May. In three weeks, Grant's men marched 180 miles, won five battles, and took 6,000 prisoners.
Grant made some attacks after bottling Vicksburg, but found the Confederates well entrenched. Preparing for a long siege, his army constructed 15 miles of trenches and enclosed Pemberton's force of 29,000 men inside the perimeter. It was only a matter of time before Grant, with 70,000 troops, captured Vicksburg. Attempts to rescue Pemberton and his force failed from both the east and west, and conditions for both military personnel and civilians deteriorated rapidly. Many residents moved to tunnels dug from the hillsides to escape the constant bombardments. Pemberton surrendered on July 4, and President Abraham Lincoln wrote that the Mississippi River "again goes unvexed to the sea."
The town of Vicksburg would not celebrate the Fourth of July for 81 years.