The Mexican American War Mr . Winchell APUSH OUR FINAL LESSON-Westward Expansion Unit

Annexation of Texas Upon annexing Texas, president Polk sent John Slidell as his special envoy to the government in Mexico City. Slidell was instructed to convince Mexico to sell the California and New Mexico territories to the US and settle the border between Texas and Mexico.

Beginning of the Dispute Mexico refused to negotiate. Mexico also disputed the border Texas had been claiming for the previous 10 years.

The War Begins The war began in very a controversial manner. The war began in June of 1845. President Polk sent general Zachary Taylor to Texas to protect the American border with Mexico.

General Antonio Lopez de Santa Ana

President James K. Polk

General Zachary Taylor

Border Dispute The U.S. and Mexico had a different opinion on where the border between Texas and Mexico was as you will see on the map that follows.

War of Aggression President Polk sent General Taylor to the area that the U.S. considered it’s border. Predictably, Taylor’s troops were attacked by the Mexican army. Polk now had reason to go to war, and enough evidence to convince Congress to declare war, despite the objections of Northern Whigs (like Lincoln).

Polk’s message to Congress “...after reiterated menaces, Mexico has passed the boundary of the United States, has invaded our territory and shed American blood upon the American soil. She has proclaimed that hostilities have commenced, and that the two nations are now at war...I invoke the prompt action of Congress to recognize the existence of the war, and to place it at the disposal of the Executive the means of prosecuting the war with vigor...”

What did the U.S. want from war with Mexico? MANIFEST DESTINY!

Political Opposition to War Many members of Congress opposed the war with Mexico. Some felt that the president had forced the U.S. into the war, which was wrong because only Congress can approve war. Others just thought it was wrong to take any territory from Mexico.

U.S. has huge technological advantage Artillery - superior large guns and better ammunition better rifles and handguns, including the colt revolver telegraph = better communications

U.S. has a huge population and economic advantage U.S. - 17 million people Mexico - 7 million people U.S. - growing economy Mexico - in debt

U.S. Soldiers Immigrants made up at least half of the enlisted men in the army 1/4 of the enlisted soldiers were Irish. The Mexicans made a strong appeal to these Catholics to switch sides arguing that they were more Catholic than American. 9,207 U.S. soldiers deserted during the war; 8.3%

Deaths during the war One out of ten American soldiers died in less than two years of service Disease accounted for 7/8 of the deaths. Crowded, unsanitary conditions and impure water led to dysentery, lice, and other diseases that spread rapidly. 12,518 American soldiers died during the war.

Map of Mexican War Battles

U.S. army goes all the way to Mexico City General Stephen Kearney succeeded in taking Santa Fe, the New Mexico territory, and southern California. John C. Fremont quickly overwthrew Mexican rule in northern California and proclaimed California an independent republic (Bear Flag Republic). Zachary Taylor’s force of 6,000 men drove the Mexican army from Texas, crossed the Rio Grande into northern Mexico, and won a major victory at Buena Vista. General Winfield Scott invaded Central Mexico and took the coastal city of Vera Cruz before capturing Mexico City.

Treaty of Guadalupe Hidalgo was signed ending the war.

The Mexican Cession

Treaty of Guadalupe Hidalgo The War was a disaster from the start for the Mexican government, but they would not give in until the capital was taken. Treaty of Guadalupe Hidalgo was signed in 1848. Mexico recognized the Rio Grande as the southern border of Texas. The US took possession of the former Mexicoan provinces of California and New Mexico and paid $15 million dollars for them.

Opposition As always…not everyone agreed. Northern Whigs opposed the treaty because they saw the war as an immoral effort to expand slavery. A few Southern Democrats disliked the treaty for the opposite reasons. They wanted the US to take ALL of Mexico.

Wilmot Proviso In the first year of the war, 1846, Pennsylvania Congressman David Wilmot proposed a bill to forbit slavery in any of the territories acquired from Mexico. It passed the House of Representatives twice, but both times was shot down by the Senate. Why do you think it wouldn’t pass through the Senate?

Gadsden Purchase 1853 agreement to buy a strip of land in what is now the southern United States so that a railroad line could be built to the Gulf of California. It cost $10 million.

Territorial Expansion

Conclusion End of unit writing prompt: Write a summative paragraph explaining how 3 different events helped contribute to growing tensions between North and South.