In the early part of 1863 Lincoln relieved Burnside of his command, and appointed General Joseph Hooker to succeed him. This officer had distinguished himself as a brilliant tactician; he was known as "fighting Joe;" but he was rash. He made a bold and successful march, crossed the Rappahannock and Rapidan rivers and advanced upon the enemy, but early in May, 1863, was defeated at Chancellorsville, in one of the bloodiest battles of the war. The Confederates were now exceedingly elated; and Lee, with a largely increased army of ninety thousand splendid fighting men, resolved on invading Pennsylvania in force. Evading Hooker, he passed through the Shenandoah Valley, and about the middle of June was in Pennsylvania before the Union forces could be gathered to oppose him. He took York and Carlisle and threatened Harrisburg. The invasion filled the North with dismay. Hooker, feeling his incompetency, and on bad terms with Halleck, the general-in-chief, asked to be relieved, and his request was at once granted. General George C. Meade was appointed his successor on June 28. Striking due north with all speed, ably supported by a remarkable group of corps-commanders and the veteran Army of the Potomac handsomely reinforced and keenly eager to fight, Meade brought Lee to bay near the village of Gettysburg, and after three days of terrific fighting, in which the losses of the two armies aggregated over forty-five thousand men, on the 3d of July he defeated Lee's army and turned it rapidly southward. This was the most decisive battle of the war, and the most bloody, finally lost by Lee through his making the same mistake that Burnside did at Fredericksburg, in attacking equal forces intrenched on a hill. Nothing was left to Lee but retreat across the Potomac, and Meade--an able but not a great captain--made the mistake that McClellan had made at Antietam in not following up his advantage, but allowing Lee to escape into Virginia. To cap the climax of Union success, on the 4th of July General Ulysses S. Grant, who had been operating against Vicksburg on the Mississippi during four months, captured that city, with thirty-two thousand prisoners, and a few days later Port Hudson with its garrison fell into his hands. The signal combination of victories filled the North with enthusiasm and the President with profoundest gratitude. It is true, Meade's failure to follow and capture Lee was a bitter disappointment to Lincoln. The Confederate commander might have been compelled to surrender to a flushed and conquering army a third larger than his own, had Meade pursued and attacked him, and the war might perhaps virtually have ended. Yet Lee's army was by no means routed, and was in dangerous mood, while Meade's losses had been really larger than his; so that the Federal general's caution does not lack military defenders. Nevertheless, he evidently was not the man that had been sought for.