The Battle of Vicksburg, Mississippi, also known as the Siege of Vicksburg, was another critical point in the war. In May of 1863, General Grant led his army across the Mississippi River and after a series of battles, forced Lt. General Pemberton’s Confederate army into and around the city of Vicksburg. After 40 days of battle, Grant’s Union forces gained control of the city as well as the Mississippi River, which President Lincoln felt was paramount to winning the entire war.