Alexandria was the highest point reached by the fleet the May before. Shreveport, the object of the present expedition, is three hundred and forty miles farther up the Red River. It was the principal depot of the Confederates west of the Mississippi, had some machine-shops and dockyards, and was fortified by a line of works of from two to three miles radius, commanding the opposite bank. Between the two places the river, which gets its name from the color of its water, flows through a fertile and populous country, the banks in many places being high, following in a very crooked channel a general southeasterly direction. In this portion of its course it has a width of seven hundred to eight hundred feet, and at low water a depth of four feet. The slope from Shreveport to Alexandria at high water is a little over a hundred feet, but immediately above the latter place there are two small rapids, called the Falls of Alexandria, which interrupt navigation when the water is low. The annual rise begins in the early winter, and from December to June the river is in fair boating condition for its usual traffic; but water enough for the gunboats and transports to pass the Falls could not be expected before the spring rise in March. The river, however, can never be confidently trusted. For twenty years before 1864 it had only once failed to rise, in 1855; but this year it was exceptionally backward, and so caused much embarrassment to the fleet. General Banks came in on the 26th of March and the last of Franklin's corps on the 28th. Smith's command was then moved on to Bayou Rapides, twenty-one miles above Alexandria. The slow rise of the river was still detaining the vessels. There was water enough for the lighter draughts, but, as the enemy was reported to have some ironclad vessels not far above, the Admiral was unwilling to let them go up until one of the heavier gunboats had passed. The Eastport was therefore sent up first, being delayed two or three days on the rocks of the rapids, and at last hauled over by main force. She at once passed ahead of Smith's corps. The Mound City, Carondelet, Pittsburg, Louisville, Chillicothe, Ozark, Osage, Neosho, Lexington, and Hindman also went above the Falls, as did some thirty transports. At this time the Marine Brigade, which was now under the army and formed part of Smith's command, was summoned back to Vicksburg, taking 3,000 men from the expedition. The river continuing to rise slowly, it was thought best to keep two lines of transports, one above and one below the Falls, and to transship stores around them. This made it necessary to establish a garrison at Alexandria, which further reduced the force for the field.