It required but a few weeks to demonstrate that however high were Halleck's professional acquirements in other respects, he was totally unfit for a commander in the field. Grant had undoubtedly been careless in not providing against the enemy's attack at Pittsburg Landing. Halleck, on the other extreme, was now doubly over-cautious in his march upon Corinth. From first to last, his campaign resembled a siege. With over one hundred thousand men under his hand, he moved at a snail's pace, building roads and breastworks, and consuming more than a month in advancing a distance of twenty miles; during which period Beauregard managed to collect about fifty thousand effective Confederates and construct defensive fortifications with equal industry around Corinth. When, on May 29, Halleck was within assaulting distance of the rebel intrenchments Beauregard had leisurely removed his sick and wounded, destroyed or carried away his stores, and that night finally evacuated the place, leaving Halleck to reap, practically, a barren victory. Nor were the general's plans and actions any more fruitful during the following six weeks. He wasted the time and energy of his soldiers multiplying useless fortifications about Corinth. He despatched Buell's wing of the army on a march toward eastern Tennessee but under such instructions and limitations that long before reaching its objective it was met by a Confederate army under General Bragg, and forced into a retrograde movement which carried it back to Louisville. More deplorable, however, than either of these errors of judgment was Halleck's neglect to seize the opportune moment when, by a vigorous movement in cooeperation with the brilliant naval victories under Flag-Officer Farragut, commanding a formidable fleet of Union war-ships, he might have completed the over-shadowing military task of opening the Mississippi River. XX The Blockade--Hatteras Inlet--Roanoke Island--Fort Pulaski--Merrimac and Monitor--The Cumberland Sunk--The Congress Burned--Battle of the Ironclads--Flag-officer Farragut--Forts Jackson and St. Philip--New Orleans Captured--Farragut at Vicksburg--Farragut's Second Expedition to Vicksburg--Return to New Orleans