Vicksburg and Port Hudson
Two sieges of Confederate bastions on the Mississippi River resulted in the Union conquest of the Mississippi Valley in July 1863. The fall of Vicksburg deeply wounded Confederate Mississippi, fractured White support for the Southern cause, and cracked open slavery in the west central part of the state. Tens of thousands of Black refugees fled plantations for the Union Army, many joining newly created Black regiments that would occupy Union posts in the valley. The fall of Vicksburg eliminated the most powerful Confederate blockade to Northern commercial use of the Mississippi River and played a pivotal role in boosting Northern and depressing Southern war morale. Problems associated with Confederate repatriation of thirty thousand paroled soldiers contributed to the breakdown of the prisoner exchange system. The fall of Port Hudson, overshadowed by Vicksburg, nevertheless completed Union conquest of the valley and allowed Northern merchant vessels to steam to New Orleans once again. The emotional benefit of these twin victories was worth the physical effort in reducing both strongholds, emboldening the North and dispiriting the South.