Unit 6-The Nation Grows Lesson 38 - War With Mexico

Review Americans began to settle in Mexico in The settlers began to grow upset with the Mexican government when they felt their rights had been violated. As a result, Texans led a revolution against Mexico, eventually earning their independence. Texas struggled as a country and hoped to be annexed by the United States. In 1845, Texas was officially annexed and became a state.

New Mexico Territory New Mexico was an area in between Texas and California that had become part of Spain’s colony in the new world. In 1610, the Spanish founded the settlement of Santa Fe. When Mexico won its independence from Spain in 1821, it inherited New Mexico.

New Mexico Territory Mexico had very little control over the territory because the settlers of New Mexico mostly governed themselves. The Spanish had tried to keep Americans away from the territory, but the new Mexican government welcomed American merchants and traders, hoping to boost the economy.

Santa Fe Trail The first American trader to reach Santa Fe in 1821 was William Becknell. He arrived loaded down with goods that he would sell for much more than he paid for in St. Louis. This new trade route became known as the Santa Fe Trail. The trail left near Independence, Missouri, crossed the prairies to the Arkansas River, continued toward the Rocky Mountains, before turning south to New Mexico.

Santa Fe Trail

Other traders followed, making the trail a busy trade route where Americans brought cloth and firearms to trade for silver, furs and mules. As trade increased, Americans started to settle the region, continuing the mentality of Manifest Destiny. As more settlers arrived, they began to want the Mexican territory of California, which would give them access to the Pacific Ocean.

California and Manifest Destiny California had been settled by mostly wealthy settlers who lived on large ranches that were known for raising cattle and horses. They often had Native Americans work the lands and raise the cattle in return for food and shelter. The ranches were similar to the southern plantations, where the ranch owners treated Native American workers almost like slaves.

California Ranchos (Ranches)

California and Manifest Destiny Americans had been visiting California for years, mostly on trading or whaling ships. The Mexican government welcomed Americans at first. Many of these Americans were agents for shipping companies, fur traders from Oregon, and merchants from New Mexico.

California and Manifest Destiny American families began to arrive in California during the 1840s. They had made the journey along the Oregon Trail, and then turned south after crossing the Rocky Mountains. California’s mild climate, beautiful landscape, and large amounts of natural resources led to Americans to talk about adding it the United States.

California Territory

California and Manifest Destiny Shippers and manufacturers hoped to build ports on the Pacific coast for trade with Asia. Many Americans saw the advantage of being bordered by the sea instead of a foreign power. President James K. Polk offered to buy California and New Mexico twice, but Mexico refused.

War With Mexico Polk, like many Americans, believed that the California and New Mexico belonged to the United States. It was the all about fulfilling the nation’s Manifest Destiny of expanding west. After Mexico refused to sell California and New Mexico, Polk decided that force would be needed to acquire these desired territories.

Polk’s Plan for War President Polk decided to provoke Mexico into taking military action first. Congress would not support a war that America started, so if Mexico attacked first then Polk could justify the war to Congress and the people. Polk used previous disputes with Mexico to push them to attack the United States.

Mexico-U.S. Disputes When the United States annexed Texas in 1845, Mexico stated that the annexation was illegal because they had never recognized the independence of Texas. Another dispute was about the Texas- Mexico border. The U.S. insisted it was the Rio Grande, while Mexico claimed it was the Nueces River, 150 miles farther north.

Mexico-U.S. Border

Polk’s Plan for War Polk sent an agent, John Slidell, to Mexico to propose a deal. The deal was to offer $30 million for California and New Mexico in return for Mexico to accept the Rio Grande as the Texas boundary. The U.S. would also take over payment of Mexico’s debts to American citizens for losses suffered during Mexico’s war for independence.

Polk and Slidell

Mexico’s Response The Mexican government refused to discuss the offer and said they would reclaim Texas for Mexico. Polk responded by ordering General Zachary Taylor and his soldiers into the disputed borderland, where Taylor built a fort. On April 24, 1846, Mexican soldiers attacked Taylor’s small army, giving Polk reason to ask Congress for a declaration of war.

General Zachary Taylor

Declaration of War On May 11, 1846, Polk told Congress that Mexico “invaded our territory and shed American blood upon American soil.” Congress passed a declaration of war against Mexico, although many Americans were divided on the issue.

A Nation Divided Democrats supported the war, while most Whigs opposed it, calling the war aggressive and unjust. Northerners accused the southern Democrats of waging war to help spread slavery. Newspapers tended to support the war, leading to many volunteers to sign up for the military. As time went on, anti-war feelings grew, especially in the North.

Attitudes Toward the War With Mexico

Polk’s Three-Part Plan First, American troops would push Mexican forces out of the disputed border region, securing the border. Second, the United States would take control of New Mexico and California. Third, American forces would take over the capital of Mexico, Mexico City.

Polk’s Three-Part Plan

Zachary Taylor accomplish the first part of the plan by February of 1847 by taking control of two major cities in the disputed border region, pushing Mexican forces out the area, securing the Texas border.

Polk’s Three-Part Plan General Stephen Watts Kearny led his troops to New Mexico and California to complete the second part of the plan. As Kearny marched along the Santa Fe Trail with 1,500 cavalry soldiers, the Mexican governor fled, allowing the Americans to capture New Mexico without firing a shot. Kearny then headed towards California.

California and the Bear Flag Republic A group of Americans seized the town of Sonoma north of San Francisco and proclaimed the independent Republic of California, which they called the Bear Flag Republic. John C. Fremont was on a military expedition, and joined the Americans in Sonoma, without any knowledge of the outbreak of war with Mexico.

Bear Flag Republic

John C. Fremont Fremont declared that he would conquer California, which upset the Californios, or Mexicans that lived in California. The Californios may have supported a revolt against the Mexican government for local control, but they were opposed to what appeared as Americans trying to seize land.

John C. Fremont

Naval Intervention In July 1846, the U.S. Navy captured the ports of Monterey and San Francisco, which allowed Commodore John Sloat to declare California annexed to the United States. Sloat and the Navy, with Fremont, sailed to San Diego. After capturing San Diego, he moved north to Los Angeles.

Naval Intervention Sloat’s forces met and joined with Kearny’s forces who were on their way from Santa Fe. After the naval forces left, many Californios acted out against the Americans who had taken the city of San Diego. Kearny’s forces arrived to stop the rebellion, and California was fully controlled by the United States in January 1847.

Polk’s Three-Part Plan With his first two goals accomplished, President Polk launched his third part of the war plan, attacking Mexico City. General Winfield Scott and his army landed on the coast of the Gulf of Mexico in March 1847, near the port of Veracruz. After taking Veracruz, Scott began the 300 mile march towards Mexico City.

General Winfield Scott

Polk’s Three-Part Plan Scott’s army had to fight their way to Mexico City against Mexican soldiers and armed citizens. Scott and his troops arrived to Mexico City in August 1847, and by mid- September the Americans had taken Mexico City, causing the Mexican government to surrender.

Losses for Both Sides The United States lost 1,721 men to battle and more than 11,000 to disease during the war. Mexico’s losses were much greater. The war cost the United States government almost $100 million, but Mexico lost half of its territory.

Treaty of Guadalupe Hidalgo Signed in February 1848, Mexico gave up all claims to Texas and agreed to the Rio Grande as the border between Texas and Mexico. Mexico also ceded, or gave up, it’s territories of California and New Mexico, known as the Mexican Cession, to the United States.

Treaty of Guadalupe Hidalgo The United States agreed to give Mexico $15 million.

Gadsden Purchase In 1853, the United States paid Mexico another $10 million for a strip of land along the southern edge of the modern day states of Arizona and New Mexico, known as the Gadsden Purchase. The Gadsden Purchase allowed the United States mainland to reach its current size. All that was needed was to settle the newly gained territories.

Conclusion As settlements and trade increased in the Southwest, conflicts with Mexico increased. These conflicts led to war between the United States and Mexico over control of these disputed territories. The United States, and it’s idea of Manifest Destiny, won and gained control of the disputed region, which is now known as the Mexican Cession. All that remained was to settle the newly acquired territories.

Assignments Answer the four review questions for this lesson. In your journal, write a paragraph about who you believe had the right to the territories of California and New Mexico. Use information from this lesson or previous lessons to support you response. You will have a Unit 6 test after you complete Lesson 39