Lee sent Jackson against the Union forces at Harper's Ferry, which is at the junction of the Potomac and Shenandoah Rivers, at which place there were stored valuable stores and munitions of war. This place was made famous by John Brown's raid a few years before. Jackson reached the neighborhood of Harper's Ferry on the morning of the 13th, and captured the town with but little opposition on the morning of the 15th. There were turned over to him 11,500 prisoners, seventy-three guns, 13,000 small arms, 200 wagons, and a large store of supplies. In this enterprise Lee had achieved an important and valuable success. Longstreet, who had advanced to Hagerstown, probably with the intention of invading Pennsylvania, was hastily recalled and sent to reënforce D. H. Hill, who was being severely pushed at Boonsborough Gap by McClellan. The defense of this path had been very necessary to Lee, but, after a desperate conflict, the Union army succeeded in forcing its way through, this being the first set-back to Lee's invasion, and he conceived at once that a great battle was at hand and began to concentrate his forces. Jackson was marching with all haste to Sharpsburg, near by Antietam Creek, having left A. P. Hill to receive the surrender at Harper's Ferry, and on the morning of the 16th the whole army, with the exception of the force of A. P. Hill, left at Harper's Ferry, was concentrated behind Antietam Creek. McClellan's army reached the opposite side of the stream on the same day. The bulk of the Confederate forces, under Longstreet and D. H. Hill, stood along the range of heights between Sharpsburg and Antietam Creek, with Longstreet on the right and Hill on the left, and Hood's division on the Hagerstown road north of Miller's farm, and near that point, in the rear, Jackson's exhausted troops were in reserve. His lines, stretching from the Hagerstown road towards the Potomac, were protected by Stuart's cavalry. General Lee had his headquarters in a tent on a hill near Sharpsburg, where the National Cemetery now is, and from that point he overlooked much of the country that was made a battlefield the next day. [Illustration: JOHN BROWN ON HIS WAY TO THE GALLOWS] Antietam Creek was spanned by four stone bridges, which were strongly guarded. McClellan made his headquarters at the fine brick mansion of Philip Pry, about two miles east of Antietam. His army was posted in front on each side, one wing under Sumner and the other under Hooker. Farther down the stream, and not far from bridge No. 3, Burnside's corps was posted. McClellan's artillery was planted on the hills in front of Sumner and Hooker. This was the general position of the contending armies on the 16th.