The War in Maryland.
Full Particulars of the Battles of Tuesday and Wednesday-
The Result Considered a Decided Union Success

        HEADQUARTERS, Tuesday Evening, Sept. 16. -During this afternoon information was received at headquarters showing that the enemy were recrossing the river and concentrating their forces on the ridge of hills outside of the town of Sharpsburg to within three miles of the main body of our army. Jackson left Harper's Ferry this morning-his troops commencing to arrive during the afternoon. When it became evident that Gen. Lee was disposed to engage our forces in battle at this point, Gen. McClellan sent for Franklin's corps and (Darius Nash) Couch's division, who were about seven miles distant, on the other side of Elk Ridge.
        There was considerable artillery firing during the day on both sides, resulting in our having about forty men killed and wounded. Among the seriously wounded was Major Arnedst, of the 1st New York Artillery, who was struck in the side by a piece of shell.
        The disposition of the troops for the impending battle was as follows: Gen. (Edwin Vose) Sumner's corps, with Banks' division, to occupy the center; Gen. Hooker's corps, with the Pennsylvania Reserves, and Franklin's corps, on the right, and (Fitz John) Porter's corps on the left of Sumner, and Burnside on the extreme left, with the view of turning the enemy's right flank. Gen. Pleasanton supported the centre with 2,500 cavalry and four batteries.
        Gen. Hooker in the afternoon crossed Antietam Creek, and took a position on the hills facing Sbarpsburg and three miles to the right of Keetsville (Keedysville). His troops got into action about dusk, which lasted two hours, during which the enemy were driven about half a mile, with considerable loss. The Pennsylvania Reserves, who were in the front, suffered much.
        The night was occupied in getting the troops in their respective positions, while ammunition trains and ambulances were forwarded to their respective commands.

The Battle of Wednesday

        WEDNESDAY EVENING, Sept. 17.-- p.m.--This has been an eventful day in the history of the rebellion. A battle has taken place, in which the Army of the Potomac has again been victorious, and which exceeds in extent any battle heretofore fought on this continent.
At the dawn of day the battle was renewed on the center and right by Generals Hooker and Sumner, who, after a sharp contest of two hours, drove the enemy about one mile. The rebels rallied shortly, and with terrible loss regained most of the ground. At this time the fearless and indomitable Gen. Hooker received a shot in the ankle and was carried from the field. The command of his troops now devolved upon Gen. Sumner. Gen. (Israel Bush) Richardson, commanding a division, was severely wounded at the same time (and soon died of the wound).
        Gen. Sumner, determined to retake the lost ground, ordered the troops to advance, which they did with a will, driving the rebels before them with great slaughter. They not only retook the ground but drove them a quarter of a mile beyond. In this action Gen. (Joseph King Fenno) Mansfield was shot through the lungs and died soon after. He was at the head of his troops with sword waving over his head, cheering on his men at the time he received his wound.
        During this time the troops under Generals Burnside and Porter had not been idle. They drove the enemy from the line of the Antietam creek on the main road to Sharpsburg, built a bridge, the old one having been burnt, and occupied the opposite bank. The loss here was considerable.
        The troops now held both sides of the creek. To get possession of the ridge of hills on the right and left hand sides of the road, from where the rebels were thundering away with artillery, was a task not easily accomplished. General Sykes's brigade, with the assistance of General Sumner, crossed the ridge on the right hand side, after considerable trouble and loss, the rebels running in all directions.
        It was now 5 O'clock, and all the enemy's positions bad been carried except the one on the left hand side of the road. To perform this duty General Burnside was assigned. The artillery opened and the infantry advanced, and the point was carried at a charge. They were, however, forced to retire before a largely superior force. Knowing that if they lost this ridge a complete rout of their army would be the result, they fought with great desperation.
        Darkness now overtook the two armies, and hostilities ceased, as if by mutual consent. The battle lasted from 5 o'clock in the morning till 7 o'clock at night, without a momentary cessation.
        The conduct of the troops, without exception, was all that any general could wish. Several regiments of new troops, who were in action for the first time, behaved admirably.
        Hundreds of Marylanders were present to witness the battle, which could be seen from many of the surrounding hills. The sharp rattle of fifty thousand muskets, and the thunder of a hundred pieces of artillery, nor the consequent excited movements of such armies is not often witnessed.
        It is impossible at this writing to form any correct idea of our loss or that of the enemy, but it is heavy on both sides. Ours will probably reach in killed and wounded 10,000. That of the enemy will not exceed it.
        The enemy's dead, which nearly all fell into our hands, were thickly strewn over the fields, laying in heaps in many places.
        Our wounded were immediately carried from the field, and the best possible attention given them.
        When Gen. Hooker fell, Gen. McClellan immediately proceeded to the right, where he was enthusiastically received, and by his presence added much to our success in recovering the ground lost. He was on the center and on the left as well, anxiously watching the progress of the battle and giving directions as to the manner of attack. He is in his tent to-night for the first time since he left Frederick city.