What did president james polk support which led to war with mexico in 1845?

on May 11, 1846, asked Congress to declare war on Mexico, which it did two days later.

After nearly two years of fighting, peace was established by the Treaty of Guadalupe Hidalgo, signed on February 2, 1848. The Rio Grande was made the southern boundary ofTexas, andCalifornia andNew Mexicowere ceded to the United States. In return, the United States paidMexico the sum of $15 million and agreed to settle all claims of U.S. citizens against Mexico.

Idon’t understand a word going on right now lol