On January 29, 1863, Grant assumed overall command. Eventually, he attempted to advance his army through water-logged terrain to bypass Vicksburg's guns. The plan of attacking Vicksburg from downriver carried great risk because upon crossing the Mississippi River, his army would be beyond the reach of most of its supply lines. On April 16, Grant ordered Admiral David Dixon Porter's gunboats south under fire from the Vicksburg batteries to meet up with troops who had marched south down the west side of the river. Grant ordered diversionary battles, confusing Pemberton and allowing Grant's army to move east across the Mississippi, landing troops at Bruinsburg. Grant's army captured Jackson, the state capital. Advancing west, Grant defeated Pemberton's army at the Battle of Champion Hill on May 16, forcing their retreat into Vicksburg. After Grant's men assaulted the entrenchments twice, suffering severe losses, they settled in for a siege lasting seven weeks. During quiet periods of the campaign, Grant would take to drinking on occasion. The personal rivalry between McClernand and Grant continued until Grant removed him from command when he contravened Grant by publishing an order without permission. Pemberton surrendered Vicksburg to Grant on July 4, 1863.