After the Texas War of Independence and the annexation of Texas to the United States, there was a great amount of hostility between the United States and Mexico, which eventually led to the Mexican American War. This war is also referred to as the U.S.- Mexican War, the Mexican War (US), and The War with Mexico (US). This war was caused by nothing more then a hunger for more land, and the belief that it was God's will for the United States to control all land "from sea to shining sea", which had become known as Manifest Destiny.
Mexico did not like the idea of Texas becoming part of the United States and the contested southern border became an issue. Civil Wars in Mexico left property damage in amount of about $4.5 million. In 1845 Polk offered to resume these debts if Mexico would recognize the Rio Grande as the southern border of Texas.
US troops marching on Monterrey during the Mexican...
By the President of the United States of America. ...
English: Battle of Chapultepec during the Mexican-...The United States claimed the border to be the Rio Grande River, while Mexico claimed land as far north as the Nueces River. President Polk sent John Slidell of Louisiana to Mexico in the later part of 1845 to correct the Texas border. Slidell worked with two of Mexico's succeeding presidents to get a hearing, but he was ignored and expelled from the country in August of 1846. The two countries both sent troops to the land that was in disagreement and a fierce standoff followed. On April 24, 1846 Mexican forces that crossed the Rio Grande ambushed a group of 63 U.S. scouts under the command of Captain Seth Thornton. This was after issuing a warning to Taylor, which was refused, commanding him to retreat back to the Nueces River. Of the 63 scouts 11 were killed, others wounded, and capturing most of...