In August 1847, as he advanced towards Mexico City, Scott defeated Santa Anna at the Battle of Contreras and the Battle of Churubusco. With the Americans at the gates of Mexico City, Trist negotiated with commissioners, but the Mexicans were willing to give up little. Scott prepared to take Mexico City, which he did in mid-September. In the United States, a heated political debate emerged regarding how much of Mexico the United States should seek to annex, Whigs such as Henry Clay arguing that the United States should only seek to settle the Texas border question, and some expansionists arguing for the annexation of all of Mexico. War opponents were also active; Whig Congressman Abraham Lincoln of Illinois introduced the "exact spot" resolutions, calling on Polk to state exactly where American blood had been shed on American soil to start the war, but the House refused to consider them.