Chapter 9 Section 3 Effects of Westward Expansion

Explain the effects of the Mexican-American War on the United States. Trace the causes and effects of the California Gold Rush. Describe the political impact of California’s application for statehood. Objectives

Treaty of Guadalupe Hidalgo. Mexico had to sell a third of its territory to the United States (1.2 million square miles). For $15 million, the United States obtained California and New Mexico. The Texas border was set at the Rio Grande. Mexico was humiliated and remained bitter toward the United States for decades.

Gadsden Purchase Territory in southern Arizona and New Mexico was purchased from Mexico for a potential route for a transcontinental railroad. The lands obtained from Mexico increased the area of the United States by a third. The land formed New Mexico, California, Nevada, Utah, Arizona, and half of Colorado.

Expansion of Slavery In 1846, the Wilmot Proviso proposed a ban on slavery in the territories obtained from Mexico. The Proviso passed in the House, but failed in the Senate. Both Whigs and Democrats voted along sectional lines. The Proviso brought the issue of slavery before Congress, which had tried avoid the topic for decades.

Gold Rush Gold was found at Sutter’s Mill near Sacramento, California. The resulting California Gold Rush brought a mass migration of 80,000 fortune hunters west. They were called forty-niners. Half traveled overland; the rest either sailed around South America or to Panama, where they crossed the isthmus and caught ships up the coast.

The Gold Rush attracted miners from South America and China. California’s population grew from 14,000 in 1847 to 225,000 in The first miners used metal pans, shovels and picks to find gold along river banks. Few became wealthy using this method, called placer mining. Merchants and traders made more money selling goods to the miners than the miners earned themselves.

Mining Camps Life in the mining camps was crude and rough. Many died of disease, especially cholera and dysentery. Fights and violence were common. Only a few of the miners were women.

Mining Process Initially, miners panned for gold. Mining soon became mechanized to make it more efficient. One method was to divert a river or stream to expose the river bed. Hydraulic mining employed jets of water to erode gravel hills into long lines of sluices which caught the gold.

Hydraulic mining left heavy sediments in the river and caused a great deal of environmental damage.

The democratic era in the gold fields did not last long. Individual prospectors were soon replaced by wealthy investors paying wages. Gold mining soon became too expensive for individual miners.

Minorities in the Gold Rush Minorities faced violence in the gold fields and discrimination in the courts. Native Americans were killed or lost their land. Others found work on farms and ranches. Old Mexican land titles were generally ignored. Most of the original Californians were dispossessed. The Chinese were targeted by a foreign miner’s tax and mob violence. Mexicans also had to pay a foreign miner’s tax.

San Francisco San Francisco became the gateway to the California gold fields. After 1848, the city grew rapidly from a tiny Spanish settlement into a major American city. Growth of San Francisco YearPopulation , , ,000

Arguments over California By October 1849, California prepared to seek admission into the Union. Most Californians opposed slavery, so California’s admission as a free state would tip the 15 slave and 15 free state balance in the U.S. Senate. Debate over the spread of slavery into the territories obtained from Mexico became a leading cause of the Civil War.