...e 26th, Gen. A. P. Hill crossed the river and drove a regiment and a battery at Mechanicsville back to the main line near Ellison's Mill, where the Nationals were strongly posted. There, on a hill, McCall 's Pennsylvania Reserves were posted, 8,500 strong, with five batteries. These, with a part of Meade's brigade, were supported by regulars under Morell and Sykes. General Reynolds held the right, ...