Caleb K's Mexican American War Timeline By MsOlson Period: Jan 1, 1845 to Jan 1, 1849 Mexican American War Mar 1, 1845 Texas Admitted to the Union John Tyler, the President of the United States, signed a congressional resolution to add Texas to the United States. Nov 1, 1845 US Tried to Buy Land (Slidell Polk) Polk sent John Slidell to Mexico to try and buy New Mexico and California, but Mexico refused to meet. Mar 1, 1846 US Troops Stationed at Disputed Border General Taylor marched past the Nueces River into disputed territory claimed by America and Mexico. May 1, 1846 US Declares War Polk asks congress to declare war and they accept. Sep 20, 1846 Battleof Monterrey General Taylor invades the City and defeats the Mexican general, Pedro de Ampudia. This victory helped redruit more troops to the American Army. Sep 14, 1847 Mexico City Surrender Mexico City was captured by General Winfield Scott, who led the army in from Vera Cruz. Feb 2, 1848 Treaty of Guadelupe Hidalgo American and Mexican negotiators meet to discuss the treaty and said that mexico must cede 55% of its land to America and in return America gave them 15 million dollars for war related costs.