For 47 days Grant strangled Vicksburg until its starving garrison surrendered on July 4 — splitting the Confederacy in two and turning the tide of the war.
Vicksburg, Mississippi sat on towering bluffs above the Mississippi River and was so well-fortified that Lincoln called it 'the key to the war' — whoever held it controlled the river and the ability to split or unite the Confederacy.
General Ulysses Grant launched two frontal assaults on Vicksburg's defenses in May 1863, both of which were repulsed with heavy Union casualties. Recognizing that direct attack was futile, he settled in for a siege, surrounding the city and cutting off all supplies.
Inside Vicksburg, civilians and soldiers alike descended into desperation. With food running out, residents dug hundreds of cave shelters in the hillsides for protection from constant Union bombardment, living underground for weeks as horses, mules, and eventually rats became food.
Confederate General John Pemberton was trapped in an impossible position — his orders from Jefferson Davis were to hold Vicksburg at all costs, but his men were dying of starvation and disease faster than combat. After 47 days, he surrendered his 29,495 surviving troops on July 4, 1863.
The timing was stunning: Vicksburg fell the day after Lee's defeat at Gettysburg, marking what historians consider the decisive turning point of the entire Civil War — in back-to-back days, the Confederacy's greatest general had been beaten in the East while the West was lost entirely.
With Vicksburg and Port Hudson (which surrendered days later) in Union hands, Lincoln declared that 'the Father of Waters again goes unvexed to the sea.' The Confederacy was now effectively severed in two, with Texas, Louisiana, and Arkansas cut off from the rest.