Answer:
The capture of Vicksburg was so important because its capture would divide the Confederacy into two halves.
Explanation:
The Battle of Vicksburg, also known as Siege of Vicksburg, took place from May 19 to July 4, 1863, around the small town of Vicksburg, Mississippi. It was the final battle of the Second Vicksburg campaign and is considered a decisive battle of the Civil War.
The battle began with two unsuccessful attacks by the Union's Tennessee army on the Confederate positions outside Vicksburg. Major General Ulysses S. Grant then began the siege of the city, which led to the surrender of the Confederate Mississippi Army defending the city after six weeks and one day on Independence Day. With the fall of Vicksburg, the Confederation lost its penultimate base on the Mississippi. With the ensuing capitulation of Port Hudson, Louisiana, the entire Mississippi Valley was under the control of the Union, and therefore the Confederacy was split in two.