From Searching for George Gordon Meade: The Forgotten Victor of Gettysburg:

Maj. Gen. William French, who had command of the III Corps following Sickles’ wounding. He did not demonstrate any particular ability (Library of Congress).

On July 22 Meade sensed an opportunity and sent a force, with William French and the III Corps in advance, through Manassas Gap with the design of slicing the long serpent of Lee’s army in half. Unfortunately, French made only a half-hearted push through the gap and didn’t reach the vicinity of Front Royal until near evening, much too late to surprise the rebels. It must have been with a heavy heart that Meade telegraphed Halleck the next day: “I regret to inform you that, on advancing this morning at daylight, the enemy had again disappeared, declining battle, and though an immediate advance was made and Front Royal occupied, nothing was seen of him but a rear guard of cavalry with a battery of artillery.”

I think my last letter to you was about the 21st or 22d, when I was embarrassed at not ascertaining anything definite in regard to Lee’s movements. The next day, the 22d, I had positive information he was moving up the Valley of the Shenandoah. I immediately put my army in motion and pushed through Manassas Gap, where I met a part of his force. By the evening of the 24th I drove his force through Manassas Gap, and debouched with the head of my army into the open country beyond, in the vicinity of Front Royal, and having collected five corps together, expected to get a fight out of him on the 25th; but on advancing on that day he was again gone, having moved his whole army and trains (principally through Strasburg), day and night, on the 23d and 24th. Of course I was again disappointed, and I presume the President will be again dissatisfied. It is evident Lee is determined not to fight me till he gets me as far away from Washington as possible and in a position where all the advantages will be on his side. I hear from officers who have been in Washington that the President offered the command of this army to Grant, who declined it, but recommended Sherman. I consider I have done a great deal in compelling Lee to abandon the Valley of Virginia, where, but for my movements, he undoubtedly would have stayed, as he did last year, employing his army in gathering in the bountiful crops of that region, and sending them to his depots at Staunton and Gordonsville for use in the winter. As soon as I can get ready I shall move on again, and it remains to be seen whether he will make a stand on the Rappahannock or behind the Rapidan. Some people think they are preparing to abandon Virginia altogether, but I doubt this.

Meade’s correspondence taken from The Life and Letters of George Gordon Meade, Major-General United States Army, Vol. 2, (New York: Charles Scribner’s Sons, 1913), p. 137. Available via Google Books.