Adam Badeau, Military history of Ulysses S. Grant from April 1861 to April 1865. Volume 2

[66] although, originally, he had not favored the Vicksburg campaign, yet when the result had demonstrated its practicability, he was willing to push its principles to the utmost. He contemplated now marching much further than Grant, when he left Grand Gulf; he proposed in some respects a grander movement. He did it, however, with the full concurrence of his chief; and aware that every preparation would await him on the coast; while Grant's campaign was countermanded, although too late, by Halleck, and he had to provide his own supplies. Grant moved with thirty-five thousand men, Sherman, with sixty thousand: Grant's force was therefore easier to subsist, but less formidable in case it met an enemy. The campaigns were, in fact, two great and heretofore unparalleled movements in war, with points of striking likeness and dissimilarity.

As to the original idea of the march, the germ was undoubtedly Grant's; but Sherman's march was a far different one from that which Grant had contemplated. The general-in-chief, as has been shown, meant at the start to open a line from Chattanooga to Mobile; but he did not at the start propose to abandon the railroads, and he never meant, or would have proposed, to leave an enemy in his rear. Sherman did conceive his peculiar march, destroying Atlanta as Cortez burnt his ships, and abandoning the railroad as Grant did the Mississippi at Vicksburg; but Grant had conceived another march much earlier. Grant first proposed that Sherman should move to Savannah whenever Canby was ready to meet him; but—and this is the greatest and most audacious part of Sherman's