Pleasonton moved forward with all his available force and occupied Middleburg and Philemont on the road to Snicker's Gap; releasing some of Duffie's men who had been captured the day before. Gregg's division encountered the enemy a short distance beyond Middleburg and drove them five miles in the direction of Ashby's Gap. There was no regular line formation, but the Indian mode of fighting was adopted on both sides, by taking advantage of every stone, fence, bush, or hollow, to shelter the men. Before the action was over Kilpatrick's command came up and took a prominent part.
Buford's division, which had advanced beyond Philemont on the Snicker's Gap road, also became warmly engaged. They turned the left flank of the rebels and pressed on successfully, but the squadron left to guard the bridge over Goose Creek was overpowered by numbers and the bridge was burned. Part of Pleasonton's force made a reconnoissance toward Warrenton and engaged Hampton's brigade there.
On the 19th Pleasonton held the positions he had gained and sent back for an infantry support.
As there were indications that the whole of Stuart's cavalry would be thrown on Gregg's division at Upperville, Pleasonton went forward with his entire force and a brigade of infantry to support it. After a series of brilliant engagements he drove Start steadily back into Ashby's Gap, where he took refuge behind Longstreet's Corps, a portion of which came up. Pleasonton then returned to Upperville and next day to Aldie. The object of these movements— to gain possession of Loudon County—having been attained, Hooker was wary, and did not propose to be lured away from his strong position, to take part in cavalry battles at a distance without a definite object. He still found it difficult to realize that Lee would still further lengthen out his long line from Richmond, and endanger his communications, by invading Pennsylvania; and he therefore waited for further developments. Lee, however, impelled by public opinion behind him, which it was hardly safe to brave, still went forward, and directed Ewell to cross the Potomac with his main body and Longstreet to fall back behind the Shenandoah to act in conjunction with Hill, who had relieved Ewell at Winchester on the 17th, against any attempt to strike the rear of his long column. Like Achilles he felt that he was only vulnerable in his heel.
Several small skirmishes occurred about this time between detachments of General Schenck's command, which picketed the north bank of the Potomac, and bands of rebel partisans. The former were surprised and captured in two or three instances. In one of these expeditions a locomotive and twenty-three cars were disabled on the Baltimore and Ohio Railroad. Imboden, too, who occupied Cumberland on the 17th, in order to favor the general plan of invasion, tore up some miles of the track west of that town, with a view to prevent any reinforcements coming from that direction.
It would have been much better for the interests of the Southern Confederacy if Lee, instead of making a downright invasion, had been content to remain in the valley and threaten Hooker with two corps, while he used the third to procure unlimited supplies in Pennsylvania, and to sever all connection between the East and West, by breaking up the railroads and cutting the telegraph wires. Such a result, however, would hardly have been sufficient to meet the expectations of the Southern people, who were bent upon nothing else than the entire subjugation of the North and the occupation of our principal cities.
Pleasonton's operations having cleared the way, Hooker moved forward promptly on the 18th to occupy the gaps. The Twelfth Corps were sent to Leesburg, the Fifth to Aldie, and the Second to Thoroughfare Gap. The other corps formed a second line in reserve. This covered Washington and gave Hooker an excellent base of operations.
In answer to his demand for reinforcements, Crawford's division of Pennsylvania Reserves, and Abercrombie's division were sent to him. As the latter was just going out of service, it was of no use. Hooker contended that his army constituted the proper defence of Washington, and that it was not necessary to keep a large force inactive there, who could be of much more service at the front. The authorities were timid, however, did not see the force of this reasoning and therefore refused to place Schenck's and Heintzelman's commands under his orders.
The enemy made a feeble attempt about this time to occupy Harper's
Ferry, but were promptly shelled out by our batteries on Maryland
Heights.
Lee having failed, on account of the discomfiture of his cavalry, in crossing the Potomac at Edwards' Ferry, was forced either to remain where he was or go forward. Impelled by public opinion he kept on his way up the Cumberland Valley. Hooker being very desirous of keeping the invasion west of the Blue Ridge, asked Heintzelman to co-operate with him by sending the 2,000 men which seemed to be of no service at Poolesville to the passes of South Mountain, which is an extension of the same range; but Heintzelman said those passes were outside of his jurisdiction, and the men were needed in Poolesville. Hooker replied somewhat angrily that he would try and do without the men. The two generals had quarreled, and there was not the best feeling between them.