The Siege of Vicksburg commenced as Union forces under General Ulysses S. Grant encircled the city of Vicksburg, Mississippi. Following several failed attempts to take the city by direct assault, Grant opted for a strategy of siege, aiming to cut off supplies and reinforcements to the Confederate defenders. Vicksburg was of critical importance due to its strategic location along the Mississippi River, which served as a vital artery for transportation and logistics for the Confederacy. The Union Army's goal was to gain control of the river to effectively split the Confederacy and improve Union supply lines.

Over the following weeks, the siege progressed as Union troops bombarded the city and effectively surrounded it. The Confederates, under Lieutenant General John C. Pemberton, faced dire conditions as food and ammunition dwindled. Civilians also suffered tremendously as they took refuge in caves and shelters to avoid artillery fire. As conditions worsened for the defenders, the Union forces were steadily bolstered by reinforcements and improved supply lines, allowing them to maintain pressure on Vicksburg.

The culmination of the siege resulted in the surrender of Pemberton’s forces on July 4, 1863, marking a pivotal turning point in the American Civil War. The Union victory at Vicksburg, alongside the earlier victory at Gettysburg, significantly boosted Northern morale and gave the Union complete control of the Mississippi River, fragmenting the Confederacy further and facilitating Union operations in the South.