War returned in March 1863 as Lieutenant General J. C. Pemberton, fearing Major General Grant’s army might bypass Vicksburg, ordered Brigadier General John Bowen to move his troops to Grand Gulf. Over the next several weeks, Bowen’s men built fortifications and mounted big guns. After failing to capture Vicksburg, Grant marched southward through Louisiana from Milliken’s Bend, intending to cross the Mississippi and take Grand Gulf as a Federal base for operations against Vicksburg from the south. To support the attack, Rear Admiral D.D. Porter ran several ironclads past the Vicksburg batteries on the night of April 16. On April 29, Porter’s ironclads opened fire on Forts Cobun and Wade. His squadron consisted of the “Pittsburgh,” “Louisville,” “Carondelet,” “Mound City,” “Tuscumbia,” “Lafayette,” and the flagship “Benton.” The bombardment lasted five hours. The “Tuscumbia” was disabled and the guns in Fort Wade were silenced, but the big guns in Fort Cobun continued firing. Unable to drive the Confederates back, Porter called off the attack. Under cover of darkness, the Federals bypassed Grand Gulf and crossed the Mississippi at Bruinsburg the next morning.