=Antietam.= A small, deep river in Maryland, which empties into the Potomac about 6 miles above Harper’s Ferry. Here was fought a terrible battle on September 17, 1862, between the Federals, under Gen. McClellan, and the Confederates, under Gen. Lee. After his victory at Bull Run, August 30, Lee invaded Maryland, and was immediately followed by McClellan. On September 16, Lee was joined by Jackson. The battle on which was staked “the invasion of Maryland,” in the view of the Federal government, but in reality the sovereignty of the Union, was near at hand. On the night of the 15th the greatest part of McClellan’s troops were in bivouac behind the heights on the left bank of the Antietam, sheltered from, but within range of, the enemy’s batteries. The morning of the 16th was occupied in reconnoissance of the enemy’s position, in rectifying the position of the Federal troops, and perfecting the arrangements for the attack. At about 3 o’clock P.M. Gen. Hooker crossed the Antietam by the bridge in the village on the Hagerstown road, and an adjacent ford, and soon gained the crest of the height on the right bank of the stream. He then turned to his left and followed down the ridge under a strong opposition, until brought to a standstill by the darkness. Gen. Mansfield was ordered to follow Gen. Hooker, so as to be in a position to support him at daybreak. At daybreak on the 17th, Gen. Hooker attacked the forces in his front, and for a time drove them before him. The enemy, however, rallying, and strengthened from their supporting columns, repulsed him. Gen. Mansfield’s corps was then drawn to Hooker’s support, and the two masses repelled the enemy. Gen. Mansfield was killed and Gen. Hooker wounded at this crisis, and obliged to withdraw from the field. Gen. Sumner’s corps soon reached this portion of the field and became hotly engaged. This corps suffered greatly at this period of the contest, Gens. Sedgwick and Crawford being wounded, and portions of the line were compelled to fall back. The enemy, however, were checked by the Federal artillery. Sumner’s corps was soon reinforced, and the lost ground was recovered. The contest in the mean time on the right was most obstinate, and the losses in this part of the field were very heavy. Gen. Burnside’s corps, on the left, was ordered early in the day to carry the bridge across the Antietam and to attack the enemy’s right. The approaches to the bridge being in the nature of a defile, and being swept by batteries of the enemy, the opposite bank of the Antietam was only reached after a severe struggle. It was afternoon before the heights were in his possession. The enemy were driven back, and a portion of their line in disorder. By the most desperate efforts, however, the enemy rallied their retreating regiments, strengthened their lines with all their available fresh troops, and opened batteries on the hills.