Causes and background
When Mexico got independence from Spain in 1821, Texas was part of Mexico. Americans and other settlers came into Texas when Mexico allowed non-Spanish settlers to settle there. After many settlers came to Texas, disputes led to the Texas Revolution in which 1836 Texas became independent. Mexico refused to recognize the republic of Texas, as an independent country. Texas soon asked to become a state of the United States.
The United States moved quickly to annex Texas after the 1844 election of James K. Polk. In his campaign, Polk had called for the "re-annexation" of Texas and the "re-occupation" of the Oregon Territory. Polk also wanted California and the rest of what is now the Southwestern United States.
In 1845, the US annexed Texas. But Mexico still did not recognize its independence or recognize the annexation by the U.S. The United States offered to buy from Mexico the land extending from Texas to the Pacific Ocean, but Mexico wanted to keep that vast area.
In 1846, a dispute over the border between Texas and Mexico resulted in armed conflict, and the Mexican–American War began. After offering to buy the territory, Polk moved U.S. troops into a place that Mexico said was not in Texas, but rather part of the Mexican state of Coahuila. The Mexican army attacked them.
The main causes of the war was the westward expansion of the United States]]. All through the 19th century Americans believed it was their right to expand westward. At the time they believed they could conquer the people already living on the land and take it for the United States. Southerners wanted to see more slave states.
In addition to small units sent to California and New Mexico, the United States sent two major armies into Mexico under the commands of General Winfield Scott and future President of the United States General Zachary Taylor.
After the U.S. had entered Mexico, the Mexican general Antonio López de Santa Anna took command of the Mexican soldiers in early 1847. The U.S. forces fought Santa Anna near Monterrey and Buena Vista. After Buena Vista, the Mexican army had many problems, including starvation, disease, and desertion. The Mexican government was unstable. In March 1847, Scott landed at Veracruz. His force included future Civil War generals Robert E. Lee, Ulysses S. Grant, Stonewall Jackson and George G. Meade, as well as Commodore Perry. Scott took Puebla in May, and took Mexico City in September after the battle of Battle of Chapultepec.
When American soldiers came to California, the Bear Flag Revolt was happening. Some Californians were attempting to leave Mexico and form their own country, as Texas had done. In July and August 1846, American soldiers captured Monterey, Yerba Buena and Los Angeles. After a counterattack by the Californios, the Americans had taken much of California by 1847. The Mexican governor of California, Pio Pico, left the state.
Peace and aftermath
The United States won the war and Mexico signed the Treaty of Guadalupe Hidalgo in 1848. The treaty gave the U.S. lands that would become the states of Arizona, California, New Mexico, Nevada, Utah, southwestern Colorado, and southwestern Wyoming. Mexico received 15 million dollars and gave up its claims to Texas.
The slavery debate in the United States became more intense with the addition of the new territory and the question of whether slavery would be legal in these new territories. Also, many of the officers who would lead troops in the American Civil War fought in the war and would use their experiences in the coming Civil War.
- "US–Mexican War, 1846–1848". PBS/KERA. Retrieved 13 November 2016.
- "The Borderlands". U.S.-Mexican War. PBS/KERA. Retrieved 29 August 2016.
- "Mexican-American War". History. A&E Television Networks, LLC. Retrieved 29 August 2016.
- "Timeline of Major Events". 1848 Mexican-American War. University of Michigan. Retrieved 29 August 2016.
- "Mexican-American War, An Investigation Utilizing the Just-War Theory". Mount Holyoke College. Retrieved 29 August 2016.