Jeff Rosenberg Mexican American Timeline By MsOlson Period: Jan 1, 1845 to Jan 1, 1849 1845-1849 Jun 16, 1845 1845 Texas Admitted to the Union President John Tyler helped to get Texas annexed but slavery stopped it from being a simple annextion. Nov 1, 1845 US Tried to Buy Land (Sidel and Polk) Slidell was told to try and purchase California by President Polk, for $25 million but was refused by Mexico. Jan 1, 1846 US Troops Stationed at Disputed President Polk ordered troops to go to the border of Mexico and Texas, this increases the tension between the U.S. and Mexico. May 1, 1846 US Declares War President Polk declaration of war in hopes of gaining valuable territories in California and New Mexico. Feb 22, 1847 Battle of Buena Vista Zachary Taylor defeats Santa Ana at Buena Vista despite being outnumbered. Sep 14, 1847 Mexico City Surrendered The US military finally captures and occupies Mexico City after a long fight of 14 hours. May 25, 1848 Treaty of Guadalupe Hidalgo Called for Mexico to cede 55% of its territory in exchange for $15 million.