 Complete the following phrase:  The main force led by Taylor continued across the Rio Grande, winning the Battle of Monterrey in September 1846. President Antonio López de Santa Anna personally marched north to fight Taylor but was defeated at the battle of Buena Vista on February 22, 1847. Meanwhile, rather than reinforce Taylors army for a continued advance, President Polk sent a second army under U.S. general Winfield Scott in March, which was transported to the port of Veracruz by sea, to begin an invasion of the countrys heartland. Scott won the Siege of Veracruz and marched toward Mexico City, winning the battles of 