This would necessarily cause the Union army to march further east to confront him, and thus prevent it from operating in heavy force in the Cumberland Valley.

Accordingly on the night of the 28th, Lee sent expresses to all his corps commanders to concentrate at Gettysburg.

If he had known that Meade was about to withdraw all the troops acting against his line of retreat he would probably have gone on and taken Harrisburg.
As the new commander of the Union army was a favorite of General Halleck, no notice was taken of his disregard of instructions in detaching the garrison of Harper's Ferry.

General Couch, who commanded the Department of the Susquehanna, was also placed under his orders, a favor which had been denied to Hooker.

The troubles of the latter were not quite over, for on his appearing in Washington to explain his action, he was immediately put under arrest for visiting the Capital without his (Halleck's) permission; a piece of petty persecution which might have been spared under the circumstances.