The Mexican-American War

• “One of the most unjust wars ever waged.” –US Grant

• The war had been “unnecessarily and unconstitutionally” begun. – Abraham Lincoln

Background

• Manifest destiny plays a big part in the lead-up to the war

• The US government secretly (and sometimes not so secretly) attempts to acquire California & Texas in the 1830s and 1840s

• A. Jackson repeatedly tries to buy Texas from Mexico, but not successful. Sam Houston & Jackson are good friends. Coincidence?!?!?!

• Mexico is internally weak, and technically still at war with Texas until an armistice was signed in 1844

So where is the border?

• The Treat of Velasco signed in 1836 set the boundary between Mexico & Texas at the Rio Grande River

• The Mexican Congress declared this treaty invalid shortly after it was signed, and proclaimed that Texas was simply a rebellious province

• In 1844, an armistice is signed between Tex & Mex, but border issues remain

California, Fremont, & Slidell

• A federally commissioned expedition arrives in Cali in winter ‘45-’46, headed by John Fremont; Fremont claims he’s looking for a seaside house for his mother, Mex officials order him to leave

• President Polk sends John Slidell to Mexico City to negotiate the purchase of Texas & Cali in Nov ‘45, government refuses

• US officially annexes Texas on 12/29/45, all but assuring a conflict with Mexico

The Thornton Affair

• Polk sends US forces to the Nueces River in July ’45 to defend a possible invasion

• By late March ‘46, these same troops were on the border of the Rio Grande near modern-day Brownsville/Matamoros

• A US scouting party was attacked on April 25th by Mexican forces

• Polk cited this bloodshed on American soil as a clear, justified cause for war, which is declared on May 13th

Mass Communications

• In previous wars, couriers, mail, & word of mouth carried most news to the masses

• By the 1840s, newspapers created an extensive & expensive systems of steamships, railroads, pony express, & telegraphs to receive war news

• The “Penny Press” was very popular with Americans; cheap daily newspapers that kept up with latest war news

• Modern war correspondent appears

• Almost all US newspapers strongly supported the war, viewing it as positive and an inevitable part of manifest destiny

• War reporters tagged along and sometimes even fought with American armies, creating a soldier-reporter hybrid

• Thus, most reporting in the US was very biased, especially by today’s standards

• Mexican newspapers mirrored the instability of the nation

• In 1845, a very popular Mexican newspaper was “El Siglo XIX”

• El Siglo XIX initially opposed war and argued for peaceful negotiations, then switched its official position

• The Mexican press helped oust Herrera & Santa Anna from power

The Telegraph

• Invented by Samuel Morse in 1837, the telegraph plays a huge part in the M-A War

• The technology had been perfected by 1844• War news could be sent by mail to the coast, a

steamship would take it to New Orleans, & the telegraph office there would broadcast it to other cities

• War news could be dispersed in just a few days

Morse Code Activity!

• You are a lowly employee of the New Orleans Telegraph company and bored out of your mind! It is April 1846....

• You see a steamship pull into the harbor....• Suddenly a man bursts into your office and

delivers an urgent message!• You must telegraph this news throughout the

US! Quick, to the telegraph!

Opposition to the War

• Don’t be confused, the M-A War was NOT Vietnam on the US homefront!

• In 1846, 200,000 men answered the call for 50,000 volunteers in New York

• War enthusiasm was HIGH, and support for the war always remained strong

• Nevertheless, a vocal minority did oppose the conflict. WHO and WHY?

The Whigs

• The Whig Party existed from 1833-1860, & was the forerunner to the Republican Party

• The party formed in the 1830s to oppose Andrew Jackson & the Democratic party

• 3 presidents were Whigs: William Henry Harrison, Zachary Taylor, Milliard Fillmore

• Based on these facts, what do you think the Whigs believed in????

Famous Whigs

• Whigs strongly believed in public education, and preferred banking and industry over agriculture

• Think of the Whigs as city slickers and the Democrats as hicks

• Many Whigs were very religious, & over time many began to oppose slavery on moral grounds

• So why would some Whigs oppose the war??

• Lincoln made a controversial speech in 1847, criticizing the war and challenging president Polk to show Congress the spot where American blood had been shed on American soil; the Whigs would not nominate Lincoln for reelection

• Popular Whig Senator Henry Clay strongly condemned the war; he lost to Polk in 1844, arguing against annexation of Texas

Other Protests

• Abolitionists were extremely vocal about their opposition, believing the war was a giant land-grab designed to extend slavery

• William Lloyd Garrison, a famous abolitionist, openly rooted for Mexico to win in his newspaper The Liberator

• The most famous protest of the war was Henry David Thoreau’s refusal to pay a poll tax; he spent one night in jail, but wrote Civil Disobedience afterwards

Soldier Protests

• Desertion in the US army was around 8%, normal by 19th century standards

• Nevertheless, there were instances of dissatisfaction with the war among soldiers

• Harsh military life in the Mexican desert caused discontent among some units

• Cruel atrocities committed by some US soldiers shocked others, & some became disillusioned

• The main difference with other wars: soldiers had more of a voice through newspapers to get this info to the public

• A (in)famous instance of soldiers protesting was the Saint Patrick Battalion

• This battalion was made up of mostly Irish & German Catholics

• Many were soldiers in the US army in the 1840s, then defected to the Mexican army before the outbreak of war

• The Irish felt like second-class citizens in the US army, but felt more at home in Mexico

• The Mexican government constantly enticed US soldiers to desert, with promises of higher pay & land grants

• The San Patricio Battalion was initially an artillery unit, & used their knowledge of US tactics against their former employers

• Santa Anna ordered the San Patricios to become an infantry unit; they often fought hard, knowing they’d be killed for treason if caught

• After the war, many were caught and executed by hanging or firing squad

The Battles

Palo Alto & Resaca de la Palma

• Fought May 8-9, 1846 near Brownsville• Gen. Mariano Arista lays siege to Fort Texas

while Gen. Taylor & most of his troops are in Port Isabel

• Arista’s strategy is to get between Fort Texas & Port Isabel, dividing the American army

• This exact scenario occurs; look on googlemaps!

• The clash at Palo Alto was won by the Americans’ use of “flying artillery,” which was artillery that could be advanced rapidly

• Mexican artillery was old, heavy, & slow• US artillery causes Mexicans to withdraw Palo Alto to a

dry stream called Resaca de la Palma• Mexican army had a better defensible position, but US

attacks & artillery are too much to overcome• Texas campaign is over, costing Mexico 335 killed & 335

wounded, US 60 killed 149 wounded

California Campaign

The Siege of Los Angeles• The Bear Flag Revolt occurred in June 1846 in Sonoma;

largely symbolic, having little actual effect• In 1846, the city (or pueblo) of Los Angeles had around 1600

citizens, mostly Californios• In August ‘46, 50 US Marines take LA easily; Mexican officials

flee north, shocking the Californios in LA• Jose Maria Flores, an officer who had remained, led a

successful insurrection against the US forcing the Marines to withdraw by Sept 30

• Though ultimately unsuccessful, the Californios proved a worthy, fierce enemy to US forces

Californios!

Battle of San Pasqual• Gen Stephen Kearney marched 200 US forces from Santa

Fe to San Diego to assist in the conquest of California• 160 Californio lancers block his advance at San Pasqual

Valley• On Dec 6, 1846 US forces charged the Californios; the

charge was unorganized & strung out, & the musket powder had been rained on

• The mules pulling the US cannons bolted; Californios used their superior horsemanship to ride down, rope, & stab US soldiers with their lances, killing 19 & wounding 15

• Despite victory, Californios retreated & US arrived in San Diego

Battle of Buena Vista

• February 1847, showdown between Taylor & Santa Anna, US nearly loses, bloodiest battle of the war

• Many of Taylor’s forces had been recalled, & his was disobeying orders to stay in Monterrey

• News from Mexico City warns Santa Anna that there is chaos in the capitol; he is forced to retreat back to Mexico City

Scott’s Mexico City Campaign

• Instead of reinforcing Taylor, Polk orders Winfield Scott to conduct a separate campaign

• Seizes the Port of Veracruz on March 29, 1847• Fights a series of engagements, and pushes

Santa Anna back to Mexico City• Between Sept 8-15, US forces lay siege to

Mexico City; main assault on the city is the storming of Chapultepec Castle on Sept 12

• Chapultepec was a fort built in 1785, and sat atop a hill overlooking the city

• Scott ordered a shelling of the fort, followed by an infantry assault the following day

• Despite a strong defense by the Mexicans, and the strong position of the castle, US forces climb the cliffs and storm the castle

• Once Chapultepec is taken, the Mexican defense collapses, & Santa Anna abandons the city

• US forces occupy Mexico until the Treat of Guadalupe Hidalgo ends the war in Feb 1848

Los Ninos Heroes• “The Boy Heroes” of

the Battle of Chapultepec

• Young boy soldiers ranging in age from 13-19 who refused to surrender Chapultepec; all died in battle

• Celebrated as national heroes in Mexico

Parting Thoughts...

• Why did the Mexican-American War occur?• Was this war a “just” war?• Why/how was the United States victorious?• Who are the heroes of the war?• What does the war mean today? Does it have

any modern meaning?