How did physical geography assist General Grant in the siege of Vicksburg ?

The Battle of Vicksburg, Mississippi, also called the Siege of Vicksburg, was the culmination of a long land and naval campaign by Union forces to capture a key strategic position during the American Civil War. President Abraham Lincoln recognized the significance of the town situated on a 200-foot bluff above the Mississippi River. He said, "Vicksburg is the key, the war can never be brought to a close until that key is in our pocket." Capturing Vicksburg would sever the Trans-Mississippi Confederacy from that east of the Mississippi River and open the river to Northern traffic along its entire length.

Explanation:

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independent innovation during the abbasid caliphate