Do Now! Wilmot Proviso: Banned slavery in any lands won from Mexico. Treaty of Guadalupe Hidalgo: Added 1.2 million square miles of territory to the United States. California Gold Rush: A mass migration of people seeking their fortunes. EQ: What were the effects of the Mexican-American War and California Gold Rush? The students will be able to recall and evaluate the concepts of Manifest Destiny and United States society divided. Ch 9 Sec 3: Effects of Territorial Expansion • In 1848, Mexico and the U.S. signed the Treaty of Guadalupe Hidalgo. Mexico gave up the northern third of their country. In 1853, the U.S. bought more territory in southern Arizona and New Mexico from Mexico as part of the Gadsden Purchase for $18 million. The new lands comprised present-day New Mexico, California, Nevada, Utah, Arizona, and half of Colorado. • The Mexican-American War had many effects. The new territories made the fight over slavery even more heated. Congress divided into pro-slavery and anti-slavery groups after the Wilmot Proviso was proposed, a bill that would have banned slavery in the new territories. • In 1848, gold was discovered in California. The discovery set off the California Gold Rush. Tens of thousands of people called forty-niners moved west. Some forty-niners came from South America. Another 25,000 laborers came from China. In just five years, California’s population jumped by more than 200,000 people. • Most of these miners had a difficult, violent life. They worked hard, earned little, and suffered from disease and poor living conditions. • At first, the miners used cheap metal pans to find gold in rivers and streams. This process was known as placer mining. Over time, however, better equipment was used. Hydraulic mining employed jets of water to erode gravel hills. • The rapid settlement of California had many effects. Native Americans were killed and terrorized by the thousands. Many Mexican Americans lost their land and their rights. • California also caused a problem when it applied for statehood. At that time, the number of slave and free states in the nation was equal. If California became a free state, it would tip the balance. This would upset proslavery states. Northern and southern congressmen debated slavery yet again. EXIT SLIP • How did the Mexican-American War serve to heighten tensions over slavery?