It was now determined by General Scott to resume the bombardment early next morning, and to attack with the columns under Quitman and Pillow.  In aid of this a storming party was detailed from Worth’s division of ten officers and two hundred and sixty men, under command of Captain Samuel McKenzie, Second Artillery, and a like detail from Twiggs’s division under Captain Silas Casey, Second Infantry, in support of Pillow’s movement, and General P.F.  Smith’s brigade of Twiggs’s division was ordered to the support of Quitman.  The bombardment was renewed early on the morning of the 13th.  Four companies of the voltigeur regiment, under Lieutenant-Colonel Joseph E. Johnston, were instructed, on the cessation of firing, to move rapidly under cover of the wall and enter the inclosure at its opening.  Four companies under Colonel Timothy P. Andrews were ordered to unite with Johnston, deploy as skirmishers, and drive the enemy from his shelter.  McKenzie was ordered to move in the rear of Johnston, with orders to follow the latter through the breach and advance rapidly and carry the main work by assault.  A force of men carrying scaling ladders were placed with Johnston.  Colonel William Trousdale, with the Eleventh and Fourteenth Regiments, and one section of Magruder’s battery, under command of Lieutenant Thomas Jonathan Jackson, was placed in position in the road leading on the left of Chapultepec to the city, and ordered to advance and prevent an advance of the enemy in that direction.  General Cadwallader was directed by General Pillow to execute the orders.  General Smith’s brigade had orders to move on the right of the column of attack and cut off the retreat of the enemy in that direction.  General Scott now notified the commanding officers of the attacking forces to be ready to move when the signal was given.  The troops moved forward promptly at the signal, and after a brave and desperate struggle its gallant defender, General Bravo, surrendered.  With the exception of Riley’s brigade, Steptoe’s battery, and the garrison at Mexcoac, all of the American army were engaged.  General Scott’s forces engaged amounted to about seven thousand five hundred men.  The Mexican authorities state that eight hundred men were in Chapultepec.  The brigades of Rangel and Pena were stationed near.  The Mexicans engaged did not probably exceed four thousand men.

[Illustration:  OPERATIONS OF THE AMERICAN ARMY IN THE VALLEY OF MEXICO in August and September 1847.]

Among the prisoners captured were Generals Monterde, Saldana, and Norriega, the former superintendent of the military school, and forty of his pupils.  On the commencement of the engagement these youths deserted their schoolrooms, and, arming themselves, joined in the defense of Chapultepec and fought with great bravery.