But they began to discern that the elements of the contest were the rights of men, and God's eternal laws; that the armies of the Union were serving in the cause which had inspired Leonidas at Thermopylæ, and Miltiades at Marathon; that the reveille which waked the soldier from his slumber was the drum-beat of all ages; that they were moving, not by the force of men's wills, not by opinions or acts of men in positions of honor and power, but by the resistless propulsion of God's immutable, changeless, eternal laws, which wither, blast, and destroy, when resisted, but which are as the dews of the morning, like sweet summer showers, vivifying, strengthening and sustaining, when accepted and obeyed. They mourned for the fallen, but they felt that they had lived for a great purpose, and had not died in vain. With defeat and disappointment there came a sublimer trust in God. There was a rekindling of faith and hope, a confidence,-- "That nothing walks with aimless feet, That not one life shall be destroyed, Or cast as rubbish to the void, When God hath made the pile complete." APPENDIX. The Army of the Potomac was organized in October, 1861. There was a reorganization in April, 1862, and again in August of that year. The organization of that portion of the army which fought the battle of the Peninsula is annexed; also those troops which fought the great battle of Antietam. By means of this table and the accompanying diagrams the reader will be able to ascertain in most instances the positions of the several regiments,--not their exact locality, for regiments in battle are often detached to other parts of the field, as reserves, pickets, skirmishers, or guards. The troops which took part in the battles of the Peninsula were the Second Corps (Sumner's), Third Corps (Heintzelman's), Fourth Corps (Keyes's), and Franklin's and McCall's divisions of the First Corps (McDowell's). McCall joined the army when it was on the Chickahominy. Shields's division of the Fifth Corps (Banks's) was sent to the Peninsula after the retreat to Harrison's Landing. It took no part in active operations there. In the reorganization after the battle of Groveton and the retreat of Pope's army to Washington, the army was composed of six corps, as described p. 175. Many of the troops which had fought on the Peninsula were left at Alexandria, and other troops--Burnside's, from North Carolina; Sherman's, from Port Royal; Cox's from Western Virginia; new troops which had been but a few days in the service, and regiments from Wadsworth's command at Washington--were put in to fill their places.