In considering the great theatre of the Civil War, attention is naturally directed to the chief contest of all, and the turning-point of the rebellion, the battle of Gettysburg, fought at the beginning of July, 1863. After the victory at Chancellorsville in May the Confederates determined to carry the war north-ward into the enemy’s country. Gettysburg is seven miles north of the southern boundary of Pennsylvania, and over forty miles from the Potomac River. To the westward is the long curving range of the South Mountain, and beyond this the great Appalachian Valley, a continuation of the Shenandoah Valley, crossing Central Pennsylvania in a curve, and here called the Cumberland Valley. In the latter are two prominent towns, Chambersburg in Pennsylvania, and Hagerstown in Maryland, on the Potomac. General Lee, in preparation for the march north-ward, gathered nearly ninety thousand men at Culpepper in Virginia, including Stuart’s cavalry force of ten thousand. General Hooker’s Union army, which had withdrawn across the Rappahannock after Chancellorsville, was then encamped opposite Frederiksburg, and one hundred and fifty miles south of Gettysburg. Lee started northward across the Potomac, but Hooker did not discover it for some days, and then rapidly followed. The Confederates crossed between June 22d and 25th, and concentrated at Hagerstown, in the Cumberland Valley, up which they made a rapid march, overrunning the entire valley to the Susquehanna River, and appearing opposite Harrisburg and Columbia. Hooker, being late in movement, crossed the Potomac lower down than Lee, on June 28th, thus making a northern race,. up the curving valleys, with Lee in advance, but on the longer route of the outer circle. There was a garrison of ten thousand men at Harper’s Ferry on the Potomac, and Hooker asked that they be added to his army ; but the War Department declined, and Hooker immediately resigned, being succeeded by General George G. Meade, who thus on the eve of the battle became the Union commander.
There are two parallel ridges bordering the plain on which Gettysburg stands. The long Seminary Ridge, stretching from north to south about a mile west of the town, gets its name from the Lutheran Theological Seminary standing upon it; and the Cemetery Ridge to the south of the town, which partly stretches up its slopes, has on its northern flat-topped hill the village cemetery, wherein the principal grave then was that of James Gettys, after whom the place was named. There is an outlying eminence called Culp’s Hill farther to the east. making, with the Cemetery Ridge, a formation bent around much like a fish-hook, with the graveyard at the bend and Culp’s Hill at the barb, while far down at the southern end of the long straight shank, as the ridge extends for two miles away, with an intervening rocky gorge called the Devil’s Den, there are two peaks, formed of tree-covered crags, known as the Little Round Top and the Big Round Top. These long parallel ridges, with the intervale and the country immediately around them, are the battle-field, which the topographical configuration well displays. It covers about twenty-five square miles, and lies mainly southwest of the town.
It was on June 28th that General Meade unexpectedly assumed command of the Union army, and he was then near the Potomac. General Ewell with the Confederate advance guard had gone up the Cumberland Valley as far as Carlisle, and his troopers were threatening Harrisburg. Nobody had opposed them, and the Confederate main body, which had got much ahead of Hooker, was at Chambersburg. Lee being far from his base, and hearing of the Union pursuit, then determined to face about and cripple his pursuers, fixing upon Gettysburg as the point of concentration. He ordered Ewell to march south from Carlisle, and the other commanders east from Chambersburg through the mountain passes. The Union cavalry advance under General Buford reached Gettysburg on June 30th, ahead of the Confederates, and Meade’s army was then stretched over the ground for more than forty miles back to the Potomac, all coming forward by forced marches. As soon as Meade became aware of Lee’s changed tactics he concluded that this extended formation was too risky, and decided to concentrate in a strong position upon the Pipe Creek hills in Maryland, about fifteen miles south of Gettysburg, and issued the necessary orders. Thus the battle opened, with each army executing a movement for concentration.