The Mexican–American War

The Mexican–American War: APUSH Study Guide

Introduction

Howdy, history buffs and adventurers! Saddle up as we embark on a journey through the wild frontier of the Mexican–American War, a clash that happened from 1846 to 1848 and forever changed the map of North America. Get ready to uncover the origins of Manifest Destiny, witness legendary battles, and understand how this war paved the way for future conflicts. Yeehaw! 🇺🇸🤠

Context to the Mexican–American War

Before we dive into the war itself, let’s set the stage with some prelude. The war's backdrop was the Texas War of Independence (1835-1836), where American settlers in Texas decided they had enough of Mexican rule and declared independence. Imagine a bunch of rowdy folks yelling, "Don’t mess with Texas!"

Heroic battles like the Alamo, where a tiny Texan group defended against a massive Mexican army, became symbols of Texan bravery. (Spoiler alert: They lost.) The Texan rallying cry "Remember the Alamo!" could be heard louder than a cowboy's yell. Equally significant was the Battle of San Jacinto, where Sam Houston's forces took down the Mexican army, leading to Texas’s independence. Think of it as the grand finale where the underdogs clinched victory!

Fast forward to 1845, and the United States decided to give Texas a big bear hug in the form of annexation. Mexico, seeing this as their annoying younger brother stealing their favorite toy, was not pleased, and tensions boiled over into the Mexican-American War.

Causes of the Mexican–American War

Alright, let’s break down why everyone was so upset and how this little Texan spat turned into a full-blown war:

First, there was the border dispute. Texas and Mexico couldn’t agree on where the line in the sand was—literally. Texas (with the backing of the U.S.) claimed the Rio Grande as the border, while Mexico insisted it was the Nueces River. You could say it was a classic case of "Whose river is it, anyway?"

Then, President James K. Polk, an expansion enthusiast (you might call him the "Ultimate Land Hoarder"), guided U.S. policy with the goal of reaching the Pacific coast. This concept, wrapped up in the divine belief of Manifest Destiny, meant the U.S. was destined to stretch from sea to shining sea, and Mexico was in the way. Picture Polk with a giant checklist and "California and New Mexico" underlined three times.

Economic and strategic interests played a huge role, too. The U.S. wanted access to rich ports in California and the Southwest's resources. Polk thought, "Why visit Mexico when you can just take it home with you?" This expansionist dream justified entering into conflict, as those regions were seen as ripe for American growth and a boost to the Southern slave economy.

When Polk sent General Zachary Taylor to the disputed territory, it was like poking a bear—only the bear spoke Spanish. Skirmishes broke out, and Congress declared war, saying, “They started it!”

The Treaty of Guadalupe Hidalgo

After a couple of years battling it out, cooler heads (and probably some exhausted soldiers) finally prevailed. The Treaty of Guadalupe Hidalgo slammed the brakes on conflict in 1848. Under this treaty, Mexico ceded a sizeable chunk of territory to the U.S. for a cool $15 million. This included present-day California, Nevada, Utah, Arizona, New Mexico, and parts of Colorado, Wyoming, Kansas, and Oklahoma. Talk about a clearance sale!

Mexican citizens in these areas were promised the continued right to their land and religion and guaranteed U.S. citizenship. Unfortunately, this was often more a "pinkie promise" than actual policy, and many faced land seizures and discrimination.

Effects of the Mexican–American War

The Mexican-American War might’ve ended, but its impact echoed through the corridors of American history, serving as both a precursor and a catalyst for future changes.

The largest and most visible impact was territorial expansion—the "Mexican Cession." With the cession, the U.S. ballooned in size, like a kid with a new Lego set, and opened these vast lands to American settlers.

Economically, the war was a boon for the U.S., fostering western expansion and paving the way for the Gold Rush. Meanwhile, poor Mexico lost more than half its territory, and their political scene became as chaotic as finding a needle in a haystack.

This expansion stoked the prickly debate over slavery. Free state or slave state? The question became a giant elephant (donkey?) in every congressional room, intensifying sectional tensions and setting the stage for the Civil War.

For Native Americans, the war brought displacement and hardship as settlers flooded into their lands faster than you can say "Manifest Destiny."

Relations between the U.S. and Mexico took a nosedive. The war left a legacy of mistrust that would simmer for decades like a burrito left too long in the microwave.

The Wilmot Proviso

As if the drama wasn’t enough, enter the Wilmot Proviso. Proposed in 1846, this proviso aimed to ban slavery in any territory acquired from Mexico. Though it passed in the House of Representatives, it bombed in the Senate. This little gem magnified sectional strife and underscored the political chess game between North and South.

Key Terms to Review

• Annexation of Texas: When Texas joined the United States in 1845 after kicking it as an independent republic.
• Battle of Coleto: A Texas Revolution battle where captured Texians later suffered the Goliad Massacre.
• Battle of San Jacinto: The clash where Sam Houston’s forces triumphed and secured Texas independence.
• Civil War: The nightmare showdown between the Union and the Confederates over states' rights and slavery (1861-1865).
• Davy Crockett: The "King of the Wild Frontier," who met his end at the Alamo.
• General Santa Anna: The on-again-off-again dictator of Mexico who tangled with Texas and the U.S.
• General Zachary Taylor: War hero and future 12th president of the United States.
• Goliad Campaign: The 1836 military events of the Texas Revolution that included the gruesome Goliad Massacre.
• Goliad Massacre: Santa Anna’s infamous execution of Texian prisoners following the Battle of Coleto.
• James Bowie: The legendary frontiersman and knife fighter who fell at the Alamo.
• Manifest Destiny: The divine belief that the U.S. was destined to expand across North America.
• Mexican Cession: The land chunk Mexico gave up in the Treaty of Guadalupe Hidalgo.
• Mexican-American War: The 1846-1848 war where the U.S. flexed its muscle and grabbed a big land chunk.
• Nueces River: The less-noticed river that Mexico claimed as Texas’s border pre-war.
• President James K. Polk: The land-hungry 11th president driving Manifest Destiny.
• Republic of Texas: The independent nation that existed from 1836 until Texas became a U.S. state.
• Rio Grande: The river that the U.S. claimed as Texas’s southern boundary.
• Sam Houston: The hero of San Jacinto and first president of the Republic of Texas.
• Texas War of Independence: The 1835-1836 rebellion of Texians against Mexican rule.
• The Alamo: The famous 1836 siege during the Texas Revolution where Texians made their last stand.
• Treaty of Guadalupe Hidalgo: The 1848 treaty ending the Mexican-American War.
• William Barret Travis: The commander who fought bravely and fell at the Alamo.
• Wilmot Proviso: The 1846 proposal to ban slavery in any Mexican-acquired territory that never quite made it.

Conclusion

The Mexican–American War was a turning point that reshuffled the deck for America and set the stage for critical national debates and conflicts. As you delve into APUSH, remember this chapter of history not just for its battles but for its far-reaching consequences. So, embrace your inner historian, study up, and may your AP exam be victorious! 🏆📚