Thus upon a given day two armies and a fleet, hundreds of miles apart, were to concentrate at a remote point far within the enemy's lines, situated on a river always difficult and uncertain of navigation, and now obstructed and fortified. Not often in the history of war is the same fundamental principle twice violated in the same campaign; yet here it was so, and even in the same orders, for after once concentrating within the enemy's lines at Alexandria, the united forces of Banks, Sherman, and Porter were actually to meet those of Steele within the enemy's lines at Shreveport, where Kirby Smith, strongly fortified moreover, was within three hundred miles, roughly speaking, of either Banks or Steele, while Steele was separated from Banks by nearly five hundred miles of hostile territory, practically unknown to any one in the Union armies, and neither commander could communicate with the other save by rivers in their rear, over a long circuit, destined to lengthen with each day's march, as they should approach their common enemy in his central stronghold. Perhaps the most remarkable thing about all this was Sherman's ready and express assent to the disregard of the first rule of the great art of which he had always been an earnest student and long past a master; yet it is to be observed that Sherman knew the Red River country better than any one in the Union armies; he knew well the scanty numbers and the scattered state of the hostile forces; with him, as well as with Admiral Porter, this movement had long been a favorite; he had indeed hoped and expected to undertake it himself; but he evidently had in mind a quick and bold movement, having for its object the destruction of the Confederate depots and workshops at Shreveport, without giving the enemy notice, breathing space, or time to concentrate. But this was not to be. On learning, at New Orleans, that Banks meant to command in person, Sherman naturally gave up all thought of accompanying the expedition, and went back to Vicksburg to get his troops ready. The contingent he had promised to send from the Army of the Tennessee he now made up of two divisions of the Sixteenth Corps, united under Mower, with Kilby Smith's division of the Seventeenth Corps, and the command of the whole he gave to A. J. Smith. As early as the 2d of March Porter assembled at the mouth of the Red River a great fleet of nineteen ironclads, including fifteen of the heavier class and four of the lighter. The fleet carried 162 guns, of which 62 were of the higher calibres, from 80-pounder rifles up to 11-inch Dahlgrens, and the combined weight of projectiles was but little less than five tons.