<P> The successful ending of the Vicksburg Campaign significantly degraded the ability of the Confederacy to maintain its war effort , as described in the Aftermath section of the campaign article . Some historians -- e.g. , Ballard , p. 308 -- suggest that the decisive battle in the campaign was actually the Battle of Champion Hill , which , once won by Grant , made victory in the subsequent siege a foregone conclusion . This action ( combined with the surrender of Port Hudson to Maj. Gen. Nathaniel P. Banks on July 9 ) yielded command of the Mississippi River to the Union forces , who would hold it for the rest of the conflict . </P>
what was the result of the battle of vicksburg
degraded the ability of the Confederacy to maintain its war effort