The following day, June 26th, had been set by General "Stonewall" Jackson as the date on which he would join Lee, and together they would fall upon the right wing of the Army of the Potomac. The Federals north of the Chickahominy were under the direct command of General Fitz John Porter. Defensive preparations had been made on an extensive scale. Field works, heavily armed with artillery, and rifle-pits, well manned, covered the roads and open fields and were often concealed by timber from the eye of the opposing army. The extreme right of the Union line lay near Mechanicsville on the upper Chickahominy. A tributary of this stream from the north was Beaver Dam Creek, upon whose left bank was a steep bluff, commanding the valley to the west. This naturally strong position, now well defended, was almost impregnable to an attack from the front. Before sunrise of the appointed day the Confederate forces were at the Chickahominy bridges, awaiting the arrival of Jackson. To reach these some of the regiments had marched the greater part of the night. For once Jackson was behind time. The morning hours came and went. Noon passed and Jackson had not arrived. At three o'clock, General A. P. Hill, growing impatient, decided to put his troops in motion. Crossing at Meadow Bridge, he marched his men along the north side of the Chickahominy, and at Mechanicsville was joined by the commands of Longstreet and D. H. Hill. Driving the Union outposts to cover, the Confederates swept across the low approach to Beaver Dam Creek. A murderous fire from the batteries on the cliff poured into their ranks. Gallantly the attacking columns withstood the deluge of leaden hail and drew near the creek. A few of the more aggressive reached the opposite bank but their repulse was severe. Later in the afternoon relief was sent to Hill, who again attempted to force the Union position at Ellerson's Mill, where the slope of the west bank came close to the borders of the little stream. From across the open fields, in full view of the defenders of the cliff, the Confederates moved down the slope. They were in range of the Federal batteries, but the fire was reserved. Every artilleryman was at his post ready to fire at the word; the soldiers were in the rifle-pits sighting along the glittering barrels of their muskets with fingers on the triggers. As the approaching columns reached the stream they turned with the road that ran parallel to the bank.