The fighting along the Sharpsburg road might have resulted in a Confederate disaster had it not been for the timely arrival of the troops of General A. P. Hill. His six brigades of Confederate veterans had been the last to leave Harper's Ferry, remaining behind Jackson's main body in order to attend to the details of the surrender. Just as the Federal Ninth Corps was in the height of its advance, a cloud of dust on Harper's Ferry road cheered the Confederates to redoubled effort. Out of the dust the brigades of Hill debouched upon the field. Their fighting blood seemed to have but mounted more strongly during their march of eighteen miles. Without waiting for orders, Hill threw his men into the fight and the progress of the Ninth Corps was stopped. Lee had counted on the arrival of Hill in time to prevent any successful attempt upon the Confederate right held by Longstreet's Corps, two-thirds of which had been detached in the thick of the fighting of the morning, when Lee's left and center suffered so severely. Burnside's delay at the bridge could not have been more fortunate for Lee if he had fixed its duration himself. Had the Confederate left been attacked at the time appointed, the outcome of Antietam could scarcely have been other than a decisive victory for the Federals. Even at the time when Burnside's tardy advance began, it must have prevailed against the weakened and wearied Confederates had not the fresh troops of A. P. Hill averted the disaster. [Illustration: AFTER THE ADVANCE] In the advance along the Sharpsburg road near the Sherrick house the 79th New York "Highlanders" deployed as skirmishers. From orchards and cornfields and from behind fences and haystacks the Confederate sharpshooters opened upon them, but they swept on, driving in a part of Jones' division and capturing a battery just before A. P. Hill's troops arrived. With these reënforcements the Confederates drove back the brave Highlanders from the suburbs of Sharpsburg, which they had reached. Stubborn Scotch blood would permit only a reluctant retreat. Sharp fighting occurred around the Sherrick house with results seen in the lower picture. Night closed the battle, both sides exhausted. [Illustration: THE SEVENTEENTH NEW YORK ARTILLERY DRILLING BEFORE THE CAPITAL COPYRIGHT, 1911, PATRIOT PUB. CO.] In the background rises the dome of the Capitol which this regiment remained to defend until it was ordered to Petersburg, in 1864. It appears in parade formation. The battery commander leads it, mounted. The battery consists of six pieces, divided into three platoons of two guns each. In front of each platoon is the platoon commander, mounted. Each piece, with its limber and caisson, forms a section; the chief of section is mounted, to the right and a little to the rear of each piece. The cannoneers are mounted on the limbers and caissons in the rear. To the left waves the notched guidon used by both the cavalry and light artillery.