The fate of the Southern army hung on the problem of holding the hill behind Jackson's brigade. On its bloody slopes his men crouched with rifles leveled and from them poured a steady flame into the ranks of the charging Union columns.
Beauregard led the right wing of his newly formed battle line and Jackson the center in a desperate charge. The Union ranks were pierced and driven, only to reform instantly and hurl their assailants back to their former position. Charge and counter-charge followed in rapid and terrible succession.
The Confederates were being slowly overwhelmed. The combined Union divisions now consisted of an enveloping battle line of twenty thousand infantry, seven companies of cavalry and twenty-four pieces of artillery, while behind them yet hung ten thousand reserves eager to rush into action.
Beauregard's combined forces defending the hill were scarcely seven thousand men. At two o'clock the desperate Southern commander succeeded in bringing up additional regiments from his right wing. Two brigades at last were thrown into the storm center and a shout rose from the hard-pressed Confederates. Again they charged, drove the Union hosts back and captured a battery of artillery.
The hill was saved and the enemy driven across the turnpike into the woods.
McDowell now hurried in a division of his reserves and reformed his battle line for the final grand assault. Once more he demonstrated his skill by throwing his right wing into a wide circling movement to envelop the Confederate position on its left flank.
The scene was magnificent. As far as the eye could reach the glittering bayonets of the Union infantry could be seen sweeping steadily through field and wood flanked by its cavalry. Beauregard watched the cordon of steel draw around his hard-pressed men and planted his regiments with desperate determination to hurl them back.
Far off in the distance rose a new cloud of dust in the direction of the Manassas railroad. At their head was lifted a flag whose folds drooped in the hot, blistering July air. They were moving directly on the rear of McDowell's circling right wing.
If they were Union reserves the day was lost.
The Southerner lifted his field glasses and watched the drooping flag now shrouded in dust—now emerging in the blazing sun. His glasses were not strong enough. He could not make out its colors.