With his army at a peak strength of 75,000 men, Lee crossed the Potomac in mid-June. Lincoln soon replaced Hooker with a Pennsylvanian, Gen. George G. Meade. By the end of June the 90,000-man Federal army was moving northward from Maryland into Pennsylvania in search of the Confederates, who had turned southward in search of supplies. Advancing from opposite directions, these two mighty forces collided at Gettysburg, Pa. For three days (July 1-3) Lee delivered one attack after another. The climax of the battle came on the afternoon of July 3. Gen. George Pickett’s 15,000 men charged across an open field against the center of the Federal line. Pickett’s assault failed, with 50% casualties, and the battle ended with this attack. Over 43,000 men were killed, wounded, or listed as missing at Gettysburg. The Army of the Potomac had won its first clear-cut victory. Coupled with the fall of Vicksburg on July 4, this defeat brought Southern morale to a new low. Lee retreated to Virginia. Both armies took strong positions on opposite banks of the Rapidan River and awaited possible movements by one another. Cavalry engagements and infantry skirmishes occupied most of the remainder of that year. [Illustration: George G. Meade (4th from right) and some of his officers at their winter headquarters in Virginia. Note the barrel used as a chimney for one of the winter huts.] 1864 In 1864 the Federal war machine moved into high gear. The two men most responsible were Abraham Lincoln, who on March 9 named U. S. Grant as supreme army commander, and Grant himself, who made immediate preparations to strangle the Confederacy. Grant’s master plan was simple: Attack. Federal forces would attack simultaneously at all points and apply constant pressure on the ever-weakening Southern states. The Confederacy, Grant reasoned, could not withstand such a continual onslaught. Grant went east to campaign with the Army of the Potomac. Gen. Sherman took over command of the western forces. Federal drives in both East and West would henceforth proceed from one consistent strategy. While these two generals mapped out details for their joint offensive, a third Federal force met defeat in one of the fiascos of the war. On March 14 Gen. Nathaniel Banks, 40,000 troops, and 50 ships started up the Red River. Their objectives were to gain control of Louisiana and East Texas, to counteract threats from the Emperor Maximilian in Mexico, and to seize large stores of cotton. The expedition was a failure in every respect. To make matters worse for the North, Nathan Bedford Forrest and his Confederate horsemen stormed Fort Pillow, Tenn., on April 12 and killed most of the Negro troops garrisoned there. Sherman dispatched all available cavalry to rid the West once and for all of the elusive Forrest. The result was the June 10 battle of Brice’s Cross Roads, Miss., in which Forrest won his greatest victory.