[187] Polk believed Taylor had not aggressively pursued the enemy and offered command of the Veracruz expedition to Scott.[188]
The lack of trust Polk had in Taylor was returned by the Whig general, who feared the partisan president was trying to destroy him. Accordingly, Taylor disobeyed orders to remain near Monterrey.[169] In March 1847, Polk learned that Taylor had continued to march south, capturing the northern Mexican town of Saltillo.[189] Continuing beyond Saltillo, Taylor's army fought a larger Mexican force, led by Santa Anna, in the Battle of Buena Vista. Initial reports gave the victory to Mexico, with great rejoicing, but Santa Anna retreated. Mexican casualties were five times that of the Americans, and the victory made Taylor even more of a military hero in the American public's eyes, though Polk preferred to credit the bravery of the soldiers rather than the Whig general.[190]
The U.S. changed the course of the war with its invasion of Mexico's heartland through Veracruz and ultimately the capture of Mexico City, following hard fighting. In March 1847, Scott landed in Veracruz, and quickly won control of the city.