Why did President Polk send General Scott into Mexico?

Answer 1

He did not want a war, but he was willing to go to war if necessary in order to gain his objective of extending the US west to California and ending the dispute over the Texas border.

Longer answer :Border issues...again.

Let me explain. See, despite Santa Anna's defeat at the hands of the Texans, the Mexican Congress refused to accept the terms. Not that they could do much beyond point fingers and sputter. Mexico vehemently warned the U.S. that if they annexed Texas (an inevitability, given the Texans' U.S. and particularly Tennessee bushwhacker attitude), then America would have itself a war with the Central American nation. Predictably, America gleefully ignored the threats, and in 1845, Texas joined the union. Again, Mexico couldn't do much more than pout like a child who didn't get their lollipop, so it did the next best thing (in their minds): break off diplomatic contact. President Polk claimed the border as the Rio Grande River, but Mexico claimed the border as the Nueces River. According to the Treaties of Velasco, the border was indeed the Rio Grande. But Mexico herself never ratified those treaties.

Polk was in a bit of a pickle. See, the U.S. recognized Texas' independence, and by extension, the Treaties of Velasco. The border was indeed the Rio Grande. But Mexico was changing the terms of the treaties by changing the border. Strange...they weren't really willing to just march back in and take Texas back, but they were willing to force the issue... Now why would they do that?

Answer: because they knew Polk could only react one way.

See, there are two reasons for this. First, America wanted Northern California. Not necessarily to control themselves, but primarily because France and England wanted it as well. America wouldn't tolerate the European colonials re-establishing their dominion on the continent (Canada notwithstanding), and they knew Europe had its sights set on the area. Mexico was weak, and would have fallen easily to a European power, either through marshal might, or coercion. It was a matter of safety.

Secondly, cotton. Actually Mexico probably wouldn't be the best place for cotton, but it WOULD be a southern territory that would be allowed slavery. Score one for the Democrats in Congress. The North vehemently opposed the war (for the most part), but this was an America that was all about concessions to the states at this time. Polk knew the NORTH wouldn't secede, but the south sure threatened it. Blocking the war would be just one more thing to add to the secessionist's list.

So, armed with that knowledge, Mexico was pretty sure of two things: one, America would attack if they gave them a reason (i.e: disputing the border), and two: that France and England would SUPPORT Mexico if America did attack. After all, Europe was already slave-free, as was Mexico. Why would England and France support a pro-slave nation over an anti-slave nation? Also, Mexico knew it was a matter of time before it lost California. Either through revolution, conquest, or treaty. France and England wanted it, and Mexico believed they'd support Mexico if they thought they could get it from them.

Mexico was flouting the American policy of no European intervention in the Americas, and threatening an all-out war. America was deeply divided, and didn't need this agitation. Polk's decision was made for him.

In 1846, Texans went to war, again.

Answer 2

To capture the Mexican rebel Francisco Villa.

Answer 3

To Purchase Alta California and Nuevo Mexico.

Answer 4

Polk wanted to add California and New Mexico to the United States. After Mexico refused to sell, the President felt that any war or threat of war would force the acquisition.

Answer 5

To force them to negotiate the sale of Alta California and Nuevo Mexico.

Answer 6

To open a second front at Veracruz.