Mexican–American War campaigns facts for kids
This article tells you about the main battles and events of the Mexican–American War, which happened between 1846 and 1848.
Contents
Introduction to the Mexican-American War
The Mexican-American War (1846–1848) was the first time the U.S. Army fought a big war far from home. This war is often forgotten because it happened just before the American Civil War. But it was very important for shaping the United States as we know it today.
After this war, the U.S. gained a huge amount of land. This included areas that are now the states of Texas, Arizona, New Mexico, and California. Parts of Colorado, Wyoming, Utah, and Nevada were also added. This new land became a big issue. People argued about whether slavery should be allowed to spread into these new territories. These disagreements helped lead to the American Civil War just 13 years later.
Many U.S. Army leaders who fought in this war became important generals in the Civil War. They learned a lot about fighting and leading armies in Mexico. The Mexican-American War lasted about 26 months. Battles took place over thousands of miles. This included northern Mexico, Mexico City, and across New Mexico and California.
Texas Campaign: The Border Battles
Palo Alto: First Big Battle (May 8, 1846)
Things were getting tense along the Rio Grande river. The U.S. said the Rio Grande was the border. Mexico said the Nueces River was the true border. In early 1846, U.S. General Zachary Taylor built a fort on the Rio Grande. It was across from the Mexican town of Matamoros.
In April, Mexican soldiers crossed the Rio Grande. They attacked a small group of U.S. dragoons. Mexican forces in Matamoros grew stronger. General Taylor worried about his supplies. So, on May 1, he moved most of his army to Point Isabel. He left a small group at the fort opposite Matamoros. The Mexicans soon attacked this fort, later called Fort Brown.
On May 7, Taylor moved to help the fort with about 2,300 men. On May 8, they met a large Mexican army. This army had about 6,000 men, led by General Mariano Arista. The battle was named after a nearby hill, Palo Alto. Taylor used his artillery (cannons) very well. The battle lasted until night. The Mexicans then pulled back. The U.S. won mainly because of its strong artillery. The U.S. lost 9 killed and 47 wounded. Mexico had over 700 casualties, including about 320 deaths.
Resaca de la Palma: A Close Fight (May 9, 1846)
The next morning, Taylor kept moving forward. He found the Mexicans a few miles away. They were in a strong defensive spot in a dry riverbed. This place was called Resaca de la Palma. In this battle, U.S. infantry (foot soldiers) did most of the fighting. Dragoons helped by taking out Mexican cannons.
Eventually, the U.S. soldiers broke through the Mexican line. The Mexican army ran towards the Rio Grande. Many drowned trying to cross the river. Taylor's army lost 33 killed and 89 wounded. Mexico reported 160 killed, 228 wounded, and 159 missing. But Americans thought Mexico lost over a thousand men.
Taylor waited until May 18 to cross the Rio Grande. When the U.S. army entered Matamoros, the Mexican forces were gone. The next goal was Monterrey. But the direct path from Matamoros was too dry. So, Taylor waited for steamboats. He moved his army about 130 km upriver to Camargo. Thousands of volunteers joined Taylor. But disease and other problems limited his force to about 6,000 men for the Monterrey campaign.
California Campaign (1846-1847)
The California Campaign (1846-1847) was fought in Mexican Alta California. This part of the war helped the U.S. gain control of California. After the war treaty in 1848 and the California Gold Rush, California became a U.S. state in 1850.
Northern Mexican Theater: Pushing South
Monterrey: A Tough City Battle (September 21, 1846)
Taylor's forces left Camargo in late August. They attacked Monterrey on September 21, 1846. The city was defended by 7,300 to 9,000 Mexican troops. General Pedro de Ampudia led them. After three days of hard fighting, Americans pushed the enemy into the central plaza.
On September 24, Ampudia offered to surrender the city. He asked that his troops be allowed to leave safely. He also asked for an eight-week break in fighting. Taylor agreed, thinking his job was just to hold northern Mexico. Mexican troops left the city the next day. Ampudia reported 367 Mexican casualties. Taylor reported 120 killed and 368 wounded for the U.S. Both numbers were probably low.
Washington criticized Taylor for agreeing to the terms. The U.S. government quickly canceled the truce. Meanwhile, other U.S. forces moved into northern Mexico. General John E. Wool led about 2,000 men from San Antonio. He reached Parras in December without fighting. Colonel Alexander William Doniphan led 850 Missouri volunteers. They won battles near El Paso and the Sacramento River. This allowed them to capture Chihuahua.
Colonel Stephen W. Kearny led the "Army of the West." This force of about 1,660 men left Fort Leavenworth, Kansas in June 1846. They captured Santa Fe, New Mexico easily on August 18. Kearny left some men to guard Santa Fe. Then he headed for California with about 300 men. On the way, he learned that U.S. Navy sailors and marines had already taken control of California. This was done with help from volunteers led by Captain John C. Fremont.
Kearny sent 200 of his men back. He continued to San Diego, arriving on December 12. He fought a tough battle at Battle of San Pasqual, losing 19 men. At San Diego, Kearny joined Commodore Robert F. Stockton. Their combined force of about 600 men took back Los Angeles, California on January 10, 1847. Three days later, the last Mexican forces in California surrendered.
By the end of 1846, much of northern Mexico was under U.S. control. A new plan was made to attack Mexico City through Vera Cruz. General Winfield Scott, the Army's top commander, took about 8,000 men from Taylor's command. Taylor was left with about 4,800 men, mostly volunteers. He gathered them south of Saltillo.
Buena Vista: A Fierce Desert Battle (February 22–23, 1847)
General Santa Anna, the President of Mexico, gathered an army of about 15,000 men. He learned that the U.S. forces near Saltillo were weak. So, in February 1847, Santa Anna marched about 200 km across the desert to attack.
Taylor quickly moved his smaller force to Buena Vista. The land there was better for defense. Santa Anna used French tactics, trying to overwhelm the American lines with large groups of soldiers. But the U.S. infantry and artillery fired heavily. After two days of very hard fighting, Santa Anna declared victory and pulled his tired army back. He lost 1,500 to 2,000 men killed and wounded. The Americans were outnumbered 3 to 1. They lost 264 killed, 450 wounded, and 26 missing. Many more of Santa Anna's troops died retreating across the desert.
Pacific Coast Campaign (1846-1848)
The Pacific Coast Campaign involved U.S. Navy operations along Mexico's Pacific Coast. It lasted from December 1846 to March 1848. The goal was to take control of the Baja California Peninsula. They also wanted to block or capture Mexican ports on the west coast. A key target was Mazatlan, a major port for imported goods.
Southeastern Campaign (1846-1848)
First Battle of Tabasco: River Blockade
Commodore Matthew C. Perry led seven ships along the coast of Tabasco state. On October 22, 1846, Perry reached the Tabasco River (now Grijalva River). He captured the town of Frontera and two Mexican ships. He left a small guard and moved towards San Juan Bautista (today's Villahermosa).
Perry arrived in San Juan Bautista on October 25. He seized five Mexican ships. Colonel Juan Bautista Traconis, the local Mexican commander, built barricades in the city. Perry realized he would have to bomb the city to drive out the Mexican army. To avoid hurting city merchants, he pulled back his forces for the next day.
On October 26, as Perry's fleet got ready to attack, Mexican forces started firing. The U.S. bombing began. It continued until evening. Before taking the city, Perry decided to leave. He returned to Frontera. There, he set up a naval blockade. This stopped food and military supplies from reaching the state capital.
Second Battle of Tabasco: Taking the City
On June 13, 1847, Commodore Perry gathered his fleet. He began moving towards the Grijalva River. They towed 47 boats carrying 1,173 landing troops. On June 15, 19 km below San Juan Bautista, the fleet sailed through an ambush easily. At a river bend called "Devil's Bend," Perry met Mexican fire from a fort. But the fleet's heavy cannons quickly scattered the Mexican force.
On June 16, Perry reached San Juan Bautista. He started bombing the city. Two ships sailed past the fort and shelled it from behind. David D. Porter led 60 sailors ashore. They captured the fort and raised the American flag. Perry and the landing force took control of the city around 2:00 PM.
Mexico City Campaign: The Final Push
Veracruz: A Major Landing (March 9–29, 1847)
General Scott's army, with 13,660 men, met at Lobos Island in February 1847. On March 2, they sailed for Veracruz. A naval force led by Commodore Matthew C. Perry escorted them. Landing operations near Veracruz began on March 9. This was the first big amphibious landing by the U.S. Army. It was unopposed. The Mexican commander, Juan Morales, kept his 4,300 men inside the city walls.
Scott chose to besiege Veracruz instead of attacking directly. This was to save lives. The city surrendered on March 27, 1847, after a heavy bombardment. The Americans lost 19 killed and 63 wounded. The Mexican military had about 80 casualties.
Cerro Gordo: A Clever Flank (April 17, 1847)
Scott began moving towards Mexico City on April 8, 1847. The first resistance was near Cerro Gordo. Santa Anna had strongly fortified an army of about 12,000 men there. The road to Jalapa ran through mountain passes. Scott quickly won the battle with a flanking move. This cut off the enemy's escape route. Many Mexicans surrendered.
Mexico had 1,000 to 1,200 casualties. Scott released 3,000 prisoners. Santa Anna and his remaining army fled into the mountains. American losses were 64 killed and 353 wounded. Scott quickly moved to Jalapa. But he had to wait there for supplies and more troops. After some weeks, he moved carefully to Puebla. Many men were sick or wounded. About 3,700 volunteers left to go home. This left Scott with only 5,820 active soldiers by late May 1847.
Scott stayed at Puebla until early August. He waited for more troops and for peace talks to finish. The talks failed. So, Scott bravely marched towards Mexico City on August 7. He left his supply line to the coast unprotected. By this time, his army had nearly 10,000 men. Santa Anna had placed his army around Mexico City. He strongly fortified the natural obstacles.
Contreras: Breaking the Line (August 18–20, 1847)
Scott first met strong resistance at Contreras. The Mexicans were finally defeated. They suffered about 700 casualties and lost 800 prisoners.
Churubusco: A Big Defeat (August 20, 1847)
Santa Anna quickly made another stand at Churubusco. He suffered a huge defeat there. His total losses for the day, including killed, wounded, and especially those who ran away, were probably as high as 10,000. Scott estimated Mexican losses at 4,297 killed and wounded. He took 2,637 prisoners. Of 8,497 Americans fighting in the battles of Contreras and Churubusco, 131 were killed, 865 wounded, and about 40 missing.
Scott suggested a ceasefire to talk about peace. Santa Anna quickly agreed. But after two weeks of talks, it was clear the Mexicans were just using the break to rest. On September 6, Scott ended discussions. He prepared to attack the capital. To do this, they needed to take Chapultepec. This was a huge stone fortress on a hill about a mile outside the city. Mexico City was defended by 18,000 to 20,000 troops. Mexicans were confident because Scott had only about 8,000 men and was far from his supplies.
Molino del Rey: A Bloody Fight (September 8, 1847)
On September 8, 1847, Americans attacked Molino del Rey. This was an important outpost of Chapultepec. It was taken after a bloody fight. Mexicans suffered about 2,000 casualties and lost 700 prisoners. Perhaps 2,000 more ran away. The smaller American force had serious losses: 124 killed and 582 wounded. But they kept attacking Chapultepec. It finally fell on September 13, 1847.
Results: The War Ends
American losses during the siege of Chapultepec were 138 killed and 673 wounded. Mexican losses in killed, wounded, and captured were about 1,800. After the fortress fell, Mexican resistance mostly ended. Mexico City authorities sent out a white flag on September 14, 1847. Santa Anna stepped down as President. The last part of his army, about 1,500 volunteers, was defeated a few days later. They tried to capture an American supply train.
On February 2, 1848, the Treaty of Guadalupe Hidalgo was signed. The U.S. Senate approved it on March 10, 1848. The Mexican Congress approved it in May. On August 1, 1848, the last American soldier went home.
In total, 1,192 American soldiers were killed in action. 529 died from wounds. 362 died from accidents. But a huge number, 11,155 soldiers, died from disease. Diseases like Yellow fever, diarrhea, dysentery, and typhoid were common. Poor sanitation in army camps made these diseases spread. Disease caused seven times more deaths than Mexican weapons. The number of Mexican soldiers who died from disease is not known, but it was likely similar or even higher.
