By this time Lincoln had read some of those authorities (including Halleck) and was prepared to challenge the general's reasoning. "I state my general idea of the war," he wrote to both Halleck and Buell, "that we have the greater numbers, and the enemy has the greater facility of concentrating forces upon points of collision; that we must fail, unless we can find some way to making our advantage an over-match for his; and that this can be only done by menacing him with superior forces at different points, at the same time; so that we can safely attack, one, or both, if he makes no change; and if he weakens one to strengthen the other, forbear to attack the strengthened one, but seize and hold the weakened one, gaining so much."
Lincoln clearly expressed here what military theorists define as "concentration in time" to counter the Confederacy's advantage of interior lines that enabled Southern forces to concentrate in space. The geography of the war required the North to operate generally on exterior lines while the Confederacy could use interior lines to shift troops to the point of danger. By advancing on two or more fronts simultaneously, Union forces could neutralize this advantage, as Lincoln understood but Halleck and Buell seemed unable to grasp.
Not until Grant became general in chief in 1864 did Lincoln have a commander in place who would carry out this strategy. Grant's policy of attacking the enemy wherever he found it also embraced Lincoln's strategy of trying to cripple the enemy as far from Richmond (or any other base) as possible rather than maneuvering to occupy or capture places. From February to June 1862, Union forces had enjoyed remarkable success in capturing Confederate territory and cities along the south Atlantic coast and in Tennessee and the lower Mississippi Valley, including the cities of Nashville, New Orleans and Memphis. But Confederate counteroffensives in the summer recaptured much of this territory (though not these cities). Clearly, the conquest and occupation of places would not win the war so long as enemy armies remained capable of reconquering them.
Lincoln viewed these Confederate offensives more as an opportunity than a threat. When the Army of Northern Virginia began to move north in the campaign that led to Gettysburg, Gen. Joseph Hooker proposed to cut in behind the advancing Confederate forces and attack Richmond. Lincoln rejected the idea. "Lee's Army, and not Richmond, is your true objective point," he wired Hooker on June 10, 1863. "If he comes toward the Upper Potomac, follow on his flank, and on the inside track, shortening your [supply] lines, whilst he lengthens his. Fight him when opportunity offers." A week later, as the enemy was entering Pennsylvania, Lincoln told Hooker that this invasion "gives you back the chance that I thought McClellan lost last fall" to cripple Lee's army far from its base. But Hooker, like McClellan, complained (falsely) that the enemy outnumbered him and failed to attack while Lee's army was strung out for many miles on the march.
Hooker's complaints compelled Lincoln to replace him on June 28 with George Gordon Meade, who punished but did not destroy Lee at Gettysburg. When the rising Potomac trapped Lee in Maryland, Lincoln urged Meade to close in for the kill. If Meade could "complete his work, so gloriously prosecuted thus far," said Lincoln, "by the literal or substantial destruction of Lee's army, the rebellion will be over."
Instead, Meade pursued the retreating Confederates slowly and tentatively, and failed to attack them before they managed to retreat safely over the Potomac on the night of July 13-14. Lincoln had been distressed by Meade's congratulatory order to his army on July 4, which closed with the words that the country now "looks to the army for greater efforts to drive from our soil every vestige of the presence of the invader." "Great God!" cried Lincoln. "This is a dreadful reminiscence of McClellan," who had proclaimed a great victory when the enemy retreated across the river after Antietam. "Will our Generals never get that idea out of their heads? The whole country is our soil." That, after all, was the point of the war.
When word came that Lee had escaped, Lincoln was both angry and depressed. He wrote to Meade: "My dear general, I do not believe you appreciate the magnitude of the misfortune involved in Lee's escape....Your golden opportunity is gone, and I am distressed immeasurably because of it."
Having gotten these feelings off his chest, Lincoln filed the letter away unsent. But he never changed his mind. And two months later, when the Army of the Potomac was maneuvering and skirmishing again over the devastated land between Washington and Richmond, the president declared that "to attempt to fight the enemy back to his intrenchments in Richmond...is an idea I have been trying to repudiate for quite a year."
Five times in the war Lincoln tried to get his field commanders to trap enemy armies that were raiding or invading northward by cutting in south of them and blocking their routes of retreat: during Stonewall Jackson's drive north through the Shenandoah Valley in May 1862; Lee's invasion of Maryland in September 1862; Braxton Bragg's and Edmund Kirby Smith's invasions of Kentucky in the same month; Lee's invasion of Pennsylvania in the Gettysburg campaign; and Jubal Early's raid to the outskirts of Washington in July 1864. Each time his generals failed him, and in most cases they soon found themselves relieved of command.
In all of these instances the slowness of Union armies trying to intercept or pursue the enemy played a key part in their failures. Lincoln expressed repeated frustration with the inability of his armies to march as light and fast as Confederate armies. Much better supplied than the enemy, Union forces were actually slowed down by the abundance of their logistics. Most Union commanders never learned the lesson pronounced by Confederate Gen. Richard Ewell that "the road to glory cannot be followed with much baggage."