The Mexican War and California After Texas won independence from Mexico in 1836, Mexico continued to claim much of its land and refused to recognize the Rio Grande River as its boundary. This caused major tension between the United States and Mexico. When Texas became a United States territory in 1845, the United States hoped that Mexico would turn over much of its other territory such as, present-day New Mexico, Arizona, Nevada, Utah, and California. President Polk believed the United States had a right to this land. Polk believed in the philosophy of Manifest Destiny, the idea that it was destiny for the United States to extend from the Atlantic Ocean to the Pacific Ocean.
Mexico refused to sell the land and instead cut its ties with the United States. In May of 1846, the United States declared war on Mexico after Mexican troops crossed the Rio Grande River (boundary between the United States and Mexico). The United States army was too strong for the Mexican army. General Zachary Taylor won many victories in northern Mexico. General Winfield Scott captured Mexico City, Mexico’s capital. Captain John C. Fremont drove the Mexican army out of California. The United States won the war easily.
The Mexican War ended in February 1848. Mexico had to give up most of its northern territory to the United States. This territory consisted of present-day California, Nevada, and Utah, as well as parts of Arizona, New Mexico, Colorado, and Wyoming. The United States agreed to pay Mexico $15 million for this land, which became known, as the Mexican Cession. Five years after the Mexican War, the United States paid Mexico another $10 million for more land in present-day southern Arizona and southwestern New Mexico. This was called the Gadsden Purchase.
With the purchase of Mexican Cession and the Gadsden Purchase, the United States now stretched across the continent, from the Atlantic Ocean to the Pacific Ocean. The problem now becomes which of these territories will be slave territories and which will outlaw slavery. This issue will soon divide the nation and lead us into war.
On January 24, 1848, one week before the Mexican War ended, James Marshall made a discovery. While clearing out a stream in California, Marshall turned up some glittering yellow flakes. The flakes were gold and there was plenty of it in the surrounding hills.
It took about a year for news to spread to the East Coast that gold had been found. But when the word arrived, thousands of people traveled the California Trail in hopes of making it rich. This movement became known as the Gold Rush. Those who arrived in California were called forty-niners, because 1849 was the peak of the rush. In the hopes of getting rich, forty-niners risked getting robbed or even killed. There was little law and order to protect them in the mining towns. Very few people found enough gold to become rich. Because of the California Gold Rush, the population of California grew quickly. In 1845, about 15,000 people lived in the territory. By 1850, (the year California became a state) there were more than 93,000 people living in California.
Directions: Answer the following questions on loose-leaf paper. Write out the question, skip a space, and then answer it. 1. What was the cause of the tension between Mexico and the United States
following the war of Texas independence?
2. Where did the United States set the boundary between Texas and Mexico?
3. Why did President Polk think the United States had a claim to some of Mexico’s
4. Who won the Mexican War?
5. What is the Mexican Cession (states that make-up this territory)?
6. How did the United States get the Mexican Cession?
7. What was the Gadsden Purchase (states that makeup this territory)?
8. From whom did the US purchase Gadsden Purchase?
9. What did James Marshall discover? Where? When?
10. Why did California’s population grow so quickly?
11. Who were the Forty-Niners?
12. What issue will divide this country in the 1850’s and 1860’s after it was built?