division, cavalry excepted, were then well advanced on the principal line of attack, was assigned the task of driving the enemy from the hill of Cerro Gordo, and cutting off their retreat by the Jalapa road; General Shields was directed to reinforce General Twiggs with one or more of the regiments of his brigade, as circumstances might render necessary; and General Worth
"The second (Twiggs') division of regulars is already advanced within easy turning distance towards the enemy's left. That division has instructions to move forward before daylight to — morrow, and take up position across the national road in the enemy's rear, so as to cutoff a retreat towards Jalapa. It may be reinforced to-day, if unexpectedly attacked in force, by regiments, — one or two, — taken from Shields' brigade of volunteers. If not, the two volunteer regiments will march for the purpose at daylight to — morrow morning, under Brigadier General Shields, who will report to Brigadier General Twiggs, on getting up with him, or to the General-in-chief, if he be in the advance.
"The remaining regiment of the volunteer brigade will receive instructions in the course of the day.
"The first division of regulars (Worth's) will follow the movement against the enemy's left at sunrise to — morrow morning.
"As already arranged, Brigadier General Pillow's brigade will march at six o'clock to — morrow morning along the route he has carefully reconnoitered, and stand ready, as soon as he hears the report of arms on our right, or sooner, if circumstances should favor him, to pierce the enemy's line of batteries at such point, — the nearer to the river the better, as he may select. Once in the rear of that line, he will turn to the right or left, or both, and attack the batteries in reverse, or, if abandoned, he will pursue the enemy with vigor until farther orders.
"Wall's field-battery and the cavalry will be held in reserve on the national road, a little out of view and range of the enemy's batteries, They will take up that position at nine o'clock in the morning.
"The enemy's batteries being carried or abandoned, all our divisions and corps will pursue with vigor.
"This pursuit may be continued many miles, until stopped by darkness, or fortified positions, towards Jalapa. Consequently, the body of the army will not return to this encampment; but be followed to — morrow afternoon, or early the next morning, by the baggage — trains of the several corps." — Extract from the order of General Scott, dated at the Plan del Rio, April 17, 1847.