Simultaneously with these movements of the Second Corps, the First and Third were put in motion, each accompanied by its own artillery force. The First Corps, lieutenant-General Longstreet commanding, left Culpeper June 15, attended by Major[M. W.]Henry's colonel[H. C.] Cabell's Major[james]Dearing's Colonel[E. Porter]Alexander's, and Major [B. F.] Eshleman's artillery battalions, the three former marching with hood's, McLaws', and Pickett's divisions, and the two later constituting a corps reserve. As the route of this corps lay along the eastern slope of the Blue Ridge, to guard the several passes of that barrier against incursions of the enemy, its artillery was subjected to serious trial from roads frequently difficult and generally rough, and marches, under extreme heat, more than usually long. Additional labor was also imposed on some of the battalions by the necessity of meeting certain demonstrations of the enemy. Actual contest beyond cavalry skirmishing he declined. The Third Corps, on June 15, left Fredericksburg en route for Culpeper and the Shenandoah Valley, via Front Royal, accompanied by its artillery battalions, viz:Lieutenant-Colonel[John J.] Garnett's, Major [W. T.] Poague's, and Lieutenant-Colonel [A. S.] Cutt's, attending the division of Generals Heth, Pender, and Anderson, and Majors [D. G.] McIntosh's and [W. J.] Pergam's battalions as a corps reserve. In this advance, general headquarters being with the First Corps, my own were thereby also chiefly regulated. On June 16, after a week at Culpeper of such artillery preparation and supervision as were requisite and practicable. I marched toward the Valley, attending near the commanding general, to by ready for such service as might be required. On the 25th, the army, having sufficiently rested in camp near Millwood and Berryvile, crossed the Potomac, the Third corps at Shepherdstown, the First Williamsport, the commanding general being with the latter, and my duties lying near him. On Wednesday, July 1, Champersburg, Pa., having been reached by easy marches and passed, after a rest of one or two days, and the army being in motion toward Gettysburg, occasional cannon-shots in that direction were heard by myself and others with the main body, as before noon we crossed the mountain. Two divisions of the Third Corps(Heth's and Pender's, the former with Pergam's artillery battalion, the later with McIntosh's) were in advance on this road; while of the Second Corps, Early's division, attended by Jones' artillery battalion, was approaching from the direction of York, and Roders' from that of Carlisle, accompanied by Carter's battalion. The advance of the Third Corps had encountered at Gettysburg a force of the enemy, and the firing heard was the beginning of a battle. Its significance, however, was not then fully understood. It might be only a passing skirmish; it might be more serious. After a brief pause near Cashtown, to see how it would prove, the commanding general, finding the cannonade to continue and increase, moved rapidly forward. I did the same, and, at his request, rode near him for instructions. Arriving near the crest of an eminence more that a mile west of the town, dismounting and leaving horses under cover, on foot we took position overlooking the field. It was, perhaps, 2 o'clock, and the battle was raging with considerable violence. The troops of the Second Corps having reached the field some time after the engagement was opened by those of the Third, Carter's and Jones' batteries were at the time of our arrival plied on the left