Final answer:
The siege at Vicksburg led to the surrender of Confederate forces, giving the Union control over the Mississippi River and marking a turning point in the Civil War.
Step-by-step explanation:
The siege at Vicksburg led to the surrender of Confederate forces. This pivotal campaign, conducted by Union General Ulysses S. Grant, resulted in the Union's control over the Mississippi River and a significant weakening of the Confederacy's ability to mount a strong offensive in the Western Theatre of the war. The capture of Vicksburg was a crucial victory for the Union cause as it cut the Confederate territory in half and fostered Grant's reputation, leading to his eventual promotion as Lincoln's leading general. This victory, alongside the Union triumph at Gettysburg, marked a turning point in the Civil War, signifying the increasing struggles the Confederacy would face as the Union solidified its strategic advantages.