Mexican-American War 1846-1848

Causes of the War Texas was annexed by the United States on December 29, 1845. Many Mexicans were afraid this was just the first step in the United States taking over all of Mexico. Texas and Mexico were still fighting over the boundaries when the United States annexed Texas. Mexico claimed the Nueces River as the boundary. Texas and the United States claimed the Rio Grande as the boundary.

Causes of the War Man U.S. citizens wanted to be repaid for damage done to their businesses and property in Mexico. U.S. leaders were angry when Mexico ordered all U.S. settlers to leave the Mexican territory of California. President James K. Polk sent John Slidell to Mexico to try to buy New Mexico and California. Mexico officials refused to meet with him.

Fighting Starts President Polk sent General Zachary Taylor to the Rio Grande to protect the U.S. border. General Taylor and 1,000 troops arrived at the Rio Grande in March 1846. There was a Mexican camp on the other side of the river. General Taylor ordered his men to build a fort along the river by present-day Brownsville.

The President and the General President James K. Polk General Zachary Taylor

Fighting Starts In April the Mexican General sent a note to General Taylor and ordered him to “return to the east bank of the Nueces River”. Taylor refused. On April 25 a force of 1,600 Mexican cavalry crossed the Rio Grande and attacked. Most U.S. soldiers were captured, but 11 were killed and 5 were wounded. The next day General Taylor sent word to Washington that the fighting had begun.

Call for War When President Polk heard about this he went to Congress and asked them to declare war on Mexico. Debate in the Congress -“American blood has been spilt on American soil!” -“American blood has been spilt on a Mexican corn field.” –Abraham Lincoln Congress declared war on May 13, 1846

Abraham Lincoln in 1846

More Fighting Before news of the declaration of war more fighting occurred. May 8-9, 1846 – General Mariano Arista attacked at Palo Alto and Resaca de la Palma (both on north side of the Rio Grande). The United States Army won both battles.

Texans in the War When fighting broke out 6,000 Texans volunteered to join the army. Many Texans wanted the chance to fight their old rival again – Antonio Lopez de Santa Anna. Texas Governor James P. Henderson temporarily left office to join and lead Texas forces. Former Texas President Mirabeau B. Lamar joined. Texas Revolutionary, Juan Seguín, was forced to join the Mexican army.

Texans in the War James P. Henderson Mirabeau B. Lamar Juan Seguín Texas Governor 1845-1847 2nd Texas President 1838-1841 Texas Revolutionary

Texas Rangers in the War Several Rangers, including Rip Ford and John Coffee Hays, joined the U.S. Army. -They were scouts for the army. Some Rangers caused problems -They wouldn’t follow orders. -They also attacked Mexican towns. General Taylor threatened to throw all the Rangers in jail. Many Mexican feared them. -They called them Los Diablos Tejanos (“The Texas Devils”).

Texas Rangers in the War

Texas Rangers in the War

U.S. Victory After winning battles in Texas, General Taylor began an offensive – a major troop advance – into northern Mexico. U.S. forces won two major battles at Monterrey and Buena Vista. At Buena Vista Santa Anna was in command of the Mexican forces and he demanded a surrender from General Taylor.

U.S. Victory Officer Thomas L. Crittenden simply replied, “General Taylor never surrenders.” After two days Santa Anna’s forces retreated.

New Battle Plan General Winfield Scott began a new strategy in the fall of 1846 Troops would land at Veracruz and march west to attack Mexico City President Polk liked his idea so much he gave General Scott 9,000 of General Taylor’s men

Plan in Action March 1847 Scott’s troops landed near Veracruz By mid-September they had captured Mexico City Scott won the battles of Veracruz, Cerro Gordo, Contreras/Padierna, Buena Vista, and Molino del Rey, then assaulted the fort of Chapultepec which surrendered on September 13, 1847. Other U.S. forces had taken control of California and parts of New Mexico

The Cost of War Major fighting ended on September 14, 1847 when U.S. troops raised the American flag over the National Palace in Mexico City Of the 116,000 U.S. soldiers 13,000 died Many of those died from disease More than 60 Texans died in battle and 270 died from disease or accidents The war with Mexico cost America $98 million

Treaty of Guadalupe Hidalgo After the capture of Mexico City U.S. diplomat, Nicholas Trist, met with Mexico’s acting president in the city of Guadalupe Hidalgo. Nicholas Trist – U.S. diplomat

Treaty of Guadalupe Hidalgo Ended the Mexican War Signed on February 2, 1848 Mexico recognized the annexation of Texas Mexico recognized the Rio Grande as the border United States agreed to pay the $3.25 million in claims of the U.S. Citizens had against Mexico

Treaty of Guadalupe Hidalgo As part of the Treaty of Guadalupe Hidalgo Mexico agreed to cede, or give up, some 529,000 square miles of its northern land to the U.S. for $15 million This is known as the Mexican Cession

Problems in America After the Mexican War debates over slavery started Pro-slavery wanted to allow slavery in the new territories Anti-slavery didn’t want to allow slavery in the new territories Texas and New Mexico started to fight over boundaries

Compromise of 1850 In 1850 Senator Henry Clay came up with a plan The federal government would pay Texas $10 million dollars to give up its claim to New Mexico The state needed the money to pay bills left over from the Republic of Texas so they agreed Also the plan said that no territories above the 30th parallel could be a slave state

Compromise of 1850