Why did the Union want to capture Vicksburg? A. to prevent trains from getting through
B. to shut down the textile mills there
C. to get closer to Richmond
D. to control the Mississippi River

D

Explanation:

After seizing pretty much every major Mississippi River stronghold, the last city remaining was Vicksburg. If they got Vicksburg, they effectively had the entire Mississippi River, which would cut the Confederacy into 2. Therefore, your answer would be D.

can you explain it better

answer; interpreting someone's past consistent with present deviance;