Mexican leaders were furious at the admission of Texas as a state in December 1845, even though it had been independent from Mexico for almost ten years. President James K. Polk was a goal-oriented guy. One of his goals was to buy California, which would give America a base on two oceans and fulfill its Manifest Destiny to stretch from sea to sea.
But Mexico wasn’t in a selling mood. So when Polk sent diplomat James Slidell to Mexico City in late 1845 with an offer to buy California for around $25 million, Mexican leaders refused to even meet with Slidell.
Provoking a war
Polk then decided to take California by force, pushing America into its first war whose primary purpose was simply to gain territory. A young Army lieutenant named Ulysses S. Grant called it “one of the most unjust [wars] ever waged by a stronger against a weaker nation.”
It took a little prompting to get it started without firing the first shot. Polk sent an “army of observation,” under the command of Gen. Zachary Taylor, to the banks of the Rio Grande River, an area that Mexico considered its territory.
The army was gradually built up until there were about 4,000 U.S. troops there in April 1846. Taylor’s soldiers managed to provoke a small attack by Mexican troops, and the war was on.
It wasn’t much of a war. The United States lost 13,000 men, 11,000 of them to disease, and won every major battle. The Mexican army was badly led, badly equipped, and badly trained. The American army, while sometimes short on supplies because Polk was a penny pincher, was very well led, chiefly by Taylor and Gen. Winfield Scott.
Taylor, whose men called him “Old Rough and Ready” because he was tough (and something of a slob), was a career soldier. So was Scott, whose nickname was “Old Fuss and Feathers” because he had a taste for pomp and showy uniforms.
Scott and Taylor were ably supported by West Point-trained officers such as Grant and Capt. Robert E. Lee, as well as others to whom the Mexican War would prove a training ground for the Civil War 15 years later.
The first major battle, at Palo Alto, gave a taste of what was to come. Taylor led 2,300 soldiers against a Mexican army of 4,500 and routed them. In a follow-up fight, a U.S. force of 1,700 scattered a Mexican force of 7,500. American losses totaled less than 50 men for the two fights; the Mexicans lost more than 1,000.
In fact, the biggest American worry was that it might have to fight Britain at the same time over a dispute in the Northwest. American officials insisted that a boundary line between America and Canada be drawn at latitude 54 degrees, 40 minutes (which would have given the United States Vancouver, British Columbia).
A slogan from Polk’s campaign, “54-40 or fight,” became popular with some of the more pugnacious members of Congress. But in July 1846, the two sides agreed to compromise at 49 degrees.
Capturing California and the Southwest
The United States then turned its full attention to acquiring California, which was rather easily captured. Many of the Mexicans in California considered themselves “Californios” first and weren’t overly concerned about a U.S. takeover.
In Mexico, meanwhile, U.S. forces kept their undefeated streak going. Mexican forces were now commanded by Gen. Antonio López de Santa Anna of Alamo infamy. Santa Anna, who had been in exile in Cuba, talked U.S. officials into helping him sneak back into Mexico, where he promised he would sell his country out. Once there, he promptly took over command of the army and vowed to crush the hated Yankees.
In September 1846, Taylor’s troops took the city of Monterrey, Mexico. In March 1847, Scott captured the fortified seaport of Vera Cruz after a three-week siege. And in September 1847, his forces captured Mexico City, all but ending the war.
The formalities were contained in the Treaty of Guadalupe Hidalgo. It gave America more than 500,000 square miles of Mexican territory (see Figure 9-1), including California, Nevada, Utah, Arizona, and parts of New Mexico, Wyoming, and Colorado. Mexico dropped claims to Texas. Perhaps to soothe a guilty conscience, Polk agreed to pay Mexico $18.25 million, about 80 percent of what he offered before the war.
Not everyone was thrilled. In Congress, a gangly representative from Illinois named Abe Lincoln attacked the war as unjust aggression.
In Massachusetts, the iconoclastic writer Henry David Thoreau refused to pay his poll tax because the money might be used to support the war. His aunt paid it for him after he spent only one night in jail, but the essay that came out of it, “Civil Disobedience,” became a handbook for non-violent protestors and passive resistance demonstrators around the world well into the next century.
Much of the dissent about the war stemmed not just from being uncomfortable about picking on Mexico, but also from fears that the war was designed to acquire more territory for the spread of slavery.
“They just want Californy / So’s to lug new slave states in / To abuse ye and to scorn ye / And to plunder ye like sin,” wrote poet James Russell Lowell in 1848.
But even as Lowell wrote, another, richer reason was lying on the bottom of a California river.