General Lee assumed command of the army on the 3d of June. A week afterward, Jackson finished the great campaign of the Valley, by defeating Generals Fremont and Shields at Port Republic.

Such had been the important services performed by the famous "Stonewall Jackson," who was to become the "right arm" of Lee in the greater campaigns of the future. Retreating, after the defeat of General Banks, and passing through Strasburg, just as Fremont from the west, and the twenty thousand men of General McDowell from the east, rushed to intercept him, Jackson had sullenly fallen back up the Valley, with all his captured stores and prisoners, and at Cross Keys and Port Republic had achieved a complete victory over his two adversaries. Fremont was checked by Ewell, who then hastened across to take part in the attack on Shields. The result was a Federal defeat and retreat down the Valley. Jackson was free to move in any direction; and his army could unite with that at Richmond for a decisive attack upon General McClellan.

The attack in question had speedily been resolved on by Lee. Any further advance of the Federal army would bring it up to the very earthworks in the suburbs of the city; and, unless the Confederate authorities proposed to undergo a siege, it was necessary to check the further advance of the enemy by a general attack.

How to attack to the best advantage was now the question. The position of General McClellan's army has been briefly stated. Advancing up the Peninsula, he had reached and passed the Chickahominy, and was in sight of Richmond. To this stream, the natural line of defence of the city on the north and east, numerous roads diverged from the capital, including the York River Railroad, of which the Federal commander made such excellent use; and General McClellan had thrown his left wing across the stream, advancing to a point on the railroad four or five miles from the city. Here he had erected heavy defences to protect that wing until the right wing crossed in turn. The tangled thickets of the White-oak Swamp, on his left flank, were a natural defence; but he had added to these obstacles, as we have stated, by felling trees, and guarding every approach by redoubts. In these, heavy artillery kept watch against an approaching enemy; and any attempt to attack from that quarter seemed certain to result in repulse. In front, toward Seven Pines, the chance of success was equally doubtful. The excellent works of the Federal commander bristled with artillery, and were heavily manned. It seemed thus absolutely necessary to discover some other point of assault; and, as the Federal right beyond the Chickahominy was the only point left, it was determined to attack, if possible, in that quarter.

An important question was first, however, to be decided, the character of the defences, if any, on General McClellan's right, in the direction of Old Church and Cold Harbor. A reconnoissance in force was necessary to acquire this information, and General Lee accordingly directed General Stuart, commanding the cavalry of the army, to proceed with a portion of his command to the vicinity of Old Church, in the Federal rear, and gain all the information possible of their position and defences.