Answer:
The correct answers are A and B. The Battle of Vicksburg was so crucial to the Union cause because gaining control of this Confederate stronghold would split the Confederacy in two, and would prevent Confederate armies from receiving vital resources.
Explanation:
The Battle of Vicksburg took place from May 19 to July 4, 1863 around the small town of Vicksburg, Mississippi. It was the last battle of the Second Vicksburg Campaign and is considered a crucial 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 to siege the city, which after six weeks and one day (on Independence Day) resulted in the capitulation of the Confederate Mississippi Army defending the city. With the fall of Vicksburg, the Confederation lost its penultimate base on the Mississippi. With the subsequent surrender of Port Hudson, Louisiana, the entire Mississippi Valley was under Union control and the Confederation was split in two. In this way, resources from agricultural areas such as Texas and Louisiana and reinforcements could not be transferred to the states of the coast, so that these were absolutely out of stock, gradually causing their defeats.
