The American Battlefield Trust’s map of the Battle of Port Gibson
Port Gibson, ten miles east of Bruinsburg on the Little Bayou Pierre River, commanded the road network between Grand Gulf and Jackson and was Maj. Gen. Ulysses S. Grant’s first objective after crossing the Mississippi. The Confederates there were commanded by Maj. Gen. John S. Bowen, who had moved a division forward from Grand Gulf to confront Grant's XVII Corps under Maj. General James B. McPherson and XIII Corps under Maj. General John A. McClernand. Fighting erupted shortly after midnight on May 1 as Union soldiers encountered Bowen's men in the dense undergrowth near Magnolia Church and continued into the next day. Bowen’s thin line covered both the Rodney and Bruinsburg Roads. Confederate Brig. Gen. Edward Tracy was killed on the Confederate right. Successive Union attacks buckled the Confederate lines. A counterattack by Col. Francis Cockrell’s Missouri regiments was repulsed in the late afternoon and the Southerners were forced from the field. The battle secured a Union beachhead east of the Mississippi River and enabled Grant to move northeastward unopposed.