To the north of the new nation was Canada, ruled by Great Britain. A treaty in 1818 established the 49th parallel, or latitude, as the border west to the Rocky Mountains. Beyond that lay the Oregon country, left to be explored and settled by citizens of both nations. Two other nations had claims on the Oregon country. Russia had established a small presence on the north coast, while Spain had a huge presence to the south, which included most of Central and South America as well as the American southwest. A treaty was negotiated with Spain in 1819. The 42nd parallel was agreed upon as the northern limit to Spanish dominion. As this treaty was being negotiated, Spanish America was in revolt, and only had five years left to live.
In the early 1800's the flames of revolution spread throughout Latin America, ignited by the American and French revolutions, and fanned by the take-over of Spain in 1808 by Napoleon. All the Spanish colonies of South America had been liberated by 1824. But, unlike the earlier American revolution, which unified the English colonies, the Spanish American revolutions fragmented South America. Only Brazil achieved independence from Portugal with relatively little violence, and only Brazil remained unified.
The Mexican revolution paralleled those in South America. It began in 1810 with a priest, Miguel Hidalgo, leading a revolution for the rights of the lower classes, the Indians and slaves. Through political manipulation by her upper class, Mexico became an independent nation in 1821.
Mexico banned further colonization in 1830. Trouble followed. Mexican strongman General Antonio Lopez de Santa Anna sent in federal troops in 1835, but the American settlers defeated them at San Antonio, and forced the Mexican army to withdraw beyond the Rio Grande river.
A few days previously, a convention had drafted a declaration of Texan Independence, adopted a flag, and made Sam Houston the new republic's military commander. Two weeks later, the Mexican troops under Urrea captured 300 Texans at Goliad. Santa Anna ordered all these American prisoners-of-war to be shot.
Santa Anna's army advanced eastward with Texas settlers fleeing before it. Sam Houston managed to keep an army of 800 men retreating east. At San Jacinto, Houston quickly turned and attacked the Mexicans, catching Santa Anna by surprise. The battle was over in eighteen minutes, with the Texans winning. The Mexicans lost about 600 men, while the Texans lost only nine. Santa Anna was taken prisoner.
With this victory Texas won its independence. Santa Anna recognized the new republic, agreeing to the borders of the original Mexican province. The Texans ratified their new constitution, legalized slavery, elected Sam Houston president, and declared that the Texas republic included all the land north of the Rio Grande river, back to its source in today's Colorado, and including Santa Fe and much of New Mexico.
Texas applied to Washington for annexation to the United States, but the northern states in Congress refused to admit another slave state. Upon reflection, Mexico withdrew her recognition of the Lone Star Republic, but she was too involved in internal conflict to attempt to regain her lost province.
Mexico signaled a willingness to talk. Polk sent an envoy, John Slidell, to Mexico City to obtain recognition of the Rio Grande border. Secretly, Slidell would offer 25 million for California, the prize Polk really wanted for the United States. At the same time, Polk was negotiating with the British for all the Oregon country, up to the frontier with Russia. He forced the issue by putting a bill through Congress limiting the joint occupancy to one more year.
Even in the face of war, Mexico underwent the sixth revolution in seven years, placing a military faction under General Parades in charge. He refused to meet with Slidell or make any deal with the Americans. Hearing of this rejection, and increasingly concerned that Mexico might sell California to Great Britain, Polk ordered Taylor further south, crossing 150 miles into the disputed area, to establish himself on the Rio Grande. A Mexican army faced him on the opposite bank. On April 25th an American scouting party was ambushed by the Mexicans. Eleven Americans were killed. This was the incident Polk was looking for. On May 11, 1846, he sent a stern war message to Congress: "After reiterated menaces, Mexico has passed the boundary of the United States, has invaded our territory and shed American blood on American soil."
Congress declared war after only two hours of debate. It is clear now that Polk baited Mexico into war over the Texas boundary in order to get California, after concluding Mexico would not sell California. He created a provocative situation which led to violence, blamed the violence on Mexico, and in the heat of the moment got Congress to declare war. Then the people accepted the war as fact.
Abraham Lincoln was elected to Congress in 1846 after the war started, but he protested the legality of the war in a series of resolutions which questioned whether the initial incident had in fact occurred on American soil. He was not reelected.
In the Mississippi valley and in the South, volunteers rushed to enlist to rally 'round the flag and take Mexican land for America! Soldiers in the regular U. S. Army, such as this captain, were supplemented by short-term volunteers from the states, particularly Texas.
Kearny's troops followed the Santa Fe Trail across the Great Plains. Then they proceeded south into the mountains, just east of their first objective. Upon hearing that the American army was nearby, the Mexican forces in Santa Fe slipped away. Santa Fe was captured without a shot fired. Having conquered New Mexico, Kearny divided his forces to move on. He took 300 men and proceeded down the Rio Grande, making a show of force, and then turned west to California. He left Alexander Doniphan behind with the majority of his troops. Doniphan proceeded south to pacify the war-like Indian tribes in southern New Mexico. He met a Mexican army near El Brazito, but it offered little resistance. Then he began a long march into Mexico.
The only problem was with Los Angeles. The Californios at Los Angeles revolted and forced the American navy to abandon Southern California. The Californios were horsemen of the finest quality. They banded together under Andres Pico, brother of former governor Pio Pico, to protect their traditional and romantic way of life.
Stockton reestablished himself at San Diego. Kearny arrived from New Mexico after a difficult passage on the Gila river. As he neared San Diego, the Californios fell on him at San Pasqual, killing or wounding one third of his men. Kearny made it to San Diego with his remaining men, and a combined force of army and navy personal, led by Stockton and Kearny, moved up the coast to recapture Los Angeles.
The Americans advanced to the San Gabriel river. Here they were set upon by the Californios. Artillery fire was exchanged between the two sides. The Californios charged bearing lances, but accurate fire by the Americans held them off, and they retired. The next day the Americans advanced to the Los Angeles river. They held themselves in a hollow square, the classic defense against cavalry. The Californios charged, but they were driven off by American fire-power for a second time. This was enough for the Californios. They surrendered Los Angeles, and a treaty was signed at Cahuenga, bringing the citizens of California into the Union without regard for their past.
The Mexican army beat him there. By the time the Americans arrived, Mexico was ready for battle on favorable ground. The battle for Monterrey raged fiercely for three days, but after intense street fighting the Americans finally won the city. Taylor allowed the Mexican army to withdraw, a decision much criticized by President Polk.
Mexico was in desperate straits. Santa Anna had been exiled to Spanish Cuba; he now returned after making a deal with Polk to work for peace. Once reestablished in Mexico City as the country's dictator, he betrayed Polk, raised an army of 20,000 men at San Louis Potosi, and marched north to destroy Taylor. In early 1847 Taylor's and Santa Anna's forces met at Buena Vista. This was the biggest battle yet, and the Americans almost lost. Repeated thrusts by Mexican cavalry on Taylor's well fortified positions were repulsed. Both armies came out badly damaged. But in the morning Santa Anna was gone, leaving the Americans to claim victory. Meanwhile Doniphan moved from New Mexico down towards Chihuahua. After a heavy artillery duel he captured the city, one week after the Buena Vista battle.
The Americans now held all of Northern Mexico, but the Mexican government would not surrender. It appeared necessary to march directly on the capital, Mexico City, to attain a decision.
Scott prepared to march on Mexico City from Veracruz, the same route followed by Cortez 300 years earlier. He disembarked from New Orleans and gathered forces at the Rio Grande and at Tampico, which had been occupied by the U.S. Navy. At Tampico he prepared amphibious forces totaling 10,000 men. He then sailed to a point just south of Veracruz. The U.S. Navy began bombardment of the city. Civilian deaths at Veracruz soon dwarfed those at the Alamo. Scott's men came ashore and occupied the city. Then they proceeded into the interior of Mexico. Though it was only 200 miles to Mexico City, the trek would take six months.
Scott's troops initially met resistance at the fortified pass of Cerro Gordo. The Americans outflanked the Mexicans, and they retreated. The Americans then pushed on to Puebla. The Mexican cavalry skirmished with them, after which Santa Anna withdrew his forces to Mexico City. Scott remained three months in Puebla to receive replacements. Then the Americans trekked on to the continental divide, 10,000 feet above sea level, overlooking Mexico City.
Scott's troops approached Mexico City. Reconnaissance units discovered that the main road was blocked by a fortified hill. The Americans withdrew. A series of daring reconnaissances revealed a passable trail around Lake Chalco. The Americans arrived at a point eight miles south of Mexico City. After losing an initial battle, Santa Anna ordered his troops to withdraw to the inner defenses of the city. An American brigade struck and scattered one arm of this withdrawal. Hot pursuit of American columns converged on the fortified bridgehead of Churubusco. Here an intense battle was won by the Americans. After a brief armistice, the Americans continued their onslaught at Molina del Rey, just west of Mexico City. Molina was a blood bath. Five days later the Americans stormed their last obstacle, the fortified hill of Chapultepec, heroically defended by the boy cadets of the Mexican military school. This ancient castle, existing from Aztec times, held the "halls of Montezuma." Scott's troops pushed through the causeways to the capital, stopping at the western gates. In the morning Santa Anna was gone. The Americans occupied the capital. The war was over.
At the same time as the Mexican war, the Mormons, persecuted in the east, trekked across the continent to settle in the valley of the Great Salt Lake. Nevada was made a state in 1864. The Mormon settlement became the state of Utah in 1896. New Mexico was admitted in 1912, as was the state of Arizona.
Winfield Scott was dismissed by Polk after the peace treaty was signed, partly to keep him out of the Presidential race. Under his brilliant military leadership an extremely competent officer corps was unintentionally trained for both sides in the coming Civil War. Robert E Lee, Ulysses S Grant, Jefferson Davis, "Stonewall" Jackson, and others were Scott and Taylor's junior officers in the Mexican war. The tactics they learned in Mexico were used again and again in the terrible fields of the Civil War.
Mexico's course in history has been a different one from that of the United States. Revolution after revolution occurred in her early years, but these involved her entire people and all the races, not just the ruling class, as in America. Benito Jaurez led Mexico in the later 1800's. He was a full-blooded Tarascan Indian. How long will it be before a Native American is President of the United States? These internal conflicts culminated in the Great Revolution of 1910 to 1917, led by Emiliano Zapata and Pancho Villa.
Today Mexico is the United States second largest trading partner. Yet friction remains, especially over the issue of immigration. As the Latino population in the American southwest increases, an area which for hundreds of years was under Spanish or Mexican rule, the shared values of these two great neighboring nations will have to overcome their history of conflict.