CausesAfter the Texas War of Independence, Mexico did not recognize the independence of Texas because its president, General Antonio Lopez de Santa Anna, was captured during the War of independence of Texas. Even though we failed to annex Texas because it would be a slave state and an imbalance between free states and slave states. Texas was finally annexed in 1845, which was one of the causes of the outbreak of the Mexican-American War. The other cause is that President James Polk wanted California, so he offered Mexico $30,000,000 for New Mexico, California and to have the Texas border at the Rio Grande. He sent an American diplomat, John Slidell, to Mexico. When John Slidell arrived in Mexico City, Mexico refused to even see or speak to him. Polk was determined to reclaim this territory from Mexico. So James Polk knew he was going to war with Mexico, but he had to get the country on his side. Polk therefore had to get Mexico to attack first. Polk sent General Zachary Taylor to build a fort on distributed territory in January 1846 to draw Mexico into attack. On April 25, 1846, Mexican cavalry attacked the fort and the U.S. Army won the battles of Palo Alto and Resaca de la Palma. Polk's plan was perfectly planned. He went to Congress on May 11 and told them that Mexico had attacked us on our soil. On May 13, 1846, Congress declared war on Mexico. War The United States was divided over the war. Northerners believed that President James Polk, who was a southerner, was trying to gain land for slaves. Other Americans thought it was a mistake to wage war against Mexico to gain more territory. Even though American citizens were divided, the United States Army was successful on the battlefield, led by Generals Ulysses S. Grant and Robert Lee who, middle of paper, won this part of the battle. General Scott's army attacked General Anaya at Churubusco later on August 20. The fighting continued all day and to the west of the battlefield the American generals were General Pillow and David Twiggs who fought to cross the Rio Churubusco. The Americans won this battle. Overall, the Americans won the entire battle.Bibliography “American Experience: The Most Watched Historical TV Series.” PBS. PBS and Web. February 7, 2014. “Battles of the War Overview.” PBS. PBS and Web. February 16, 2014. “Mexican-American War.” History.com. A&E Television Networks, and Web. February 6. 2014. .