By then , the Mexicans had abandoned their outer defenses on the east side of Monterrey , concentrating in the Plaza Mayor .
John A. Quitman 's brigade held eastern Monterrey by 11 am .
By then , the Mexicans had abandoned their outer defenses on the east side of Monterrey , concentrating in the Plaza Mayor , and John A. Quitman 's brigade held eastern Monterrey by 11 am .