Thornton Affair

The Thornton Affair, also known as the Thornton Skirmish, was an incident between the military forces of the United States and Mexico. It served as the primary justification for U.S. President James K. Polk's declaration of war against Mexico in 1846, sparking the Mexican-American War.

The incident is clouded by over a century and a half of propaganda, half truths, and great exaggerations by the participants on both sides. However, it can be ascertained that the event occurred sometime around dusk on April 25, 1846, and continued into the early hours of April 26.

Background

Before and throughout the Mexican-American war, the state of Texas (and previously the Republic of Texas) was considered by Mexico to be a rebelling Mexican province.

A condition of the Adams-Onis Treaty of 1819 between Spain and the United States was that the U.S. relinquished any claims to Texas. Independent Mexico inherited Spain's prior agreement.

But Mexico's military defeat in the Texas revolution had complicated matters. Mexican President Antonio Lopez de Santa Anna had been defeated and captured, and he had agreed to the Rio Grande border in the Treaties of Velasco. However, the Mexican Congress maintained Santa Anna had no authority to enter into such a treaty. Mexico officially rejected it as invalid and continued to assert a claim over Texas.

The United States regarded the Treaties of Velasco as valid and maintained that even if they were not ratified by the Mexican Congress, a state of war continued to exist between the Republic of Texas and Mexico, a war both Texas and Mexico continued to wage after the Battle of San Jacinto and prior to annexation of Texas by the United States. By October 1845, 4000 troops, nearly half the U.S. Army, under orders of President Polk, were positioned on the north side of the Rio Grande.

Battle

A company of about 70 U.S. Dragoons commanded by Captain Seth Thornton was ordered to scout an area twenty miles (30 km) northwest of what later became Brownsville, Texas. On April 25, the Dragoons, acting on the advice of a local guide, investigated an abandoned hacienda. Two thousand Mexican soldiers under the command of Colonel Anastasio Torrejón were encamped in and around the hacienda, and fighting broke out. Both sides fought ferociously, but the greatly outnumbered U.S. unit was forced to surrender after several hours of resisting.

Aftermath

In the fierce encounter, 16 U.S. Dragoons were killed and 5 wounded (including Captain Thornton). Mexican casualties are unknown. Thornton and 49 of his men were taken prisoner and held at Matamoros, Tamaulipas. Upon learning of the incident, President Polk asked for a declaration of war before a joint session of the United States Congress, summing up the need for war by famously stating:

:"The cup of forbearance had been exhausted even before the recent information from the frontier of the Del Norte [Rio Grande] . But now, after reiterated menaces, Mexico has passed the boundary of the United States, has invaded our territory and shed American blood upon the American soil. She has proclaimed that hostilities have commenced, and that the two nations are now at war.".

On May 13, 1846, Congress declared war on Mexico, despite protests by the Mexican government that Thornton had crossed the border into Mexican Texas, which Mexico claimed began south of the Nueces River, the historical border of the province of Texas. Opposition also existed in the United States, with one senator declaring that the affair had been "as much an act of aggression on our part as is a man's pointing a pistol at another's breast". [cite web|url= http://www.digitalhistory.uh.edu/mexican_voices/voices_display.cfm?id=55|title=A Controversial War|publisher= [http://www.digitalhistory.uh.edu/ Digital History] |date=|accessdate=10 August|accessyear=2008] The ensuing Mexican-American War was waged from 1846-1848 with the loss of many thousands of lives and the loss to Mexico of all of its sparsely populated northern provinces. The Treaty of Guadalupe Hidalgo which ended the war established the Rio Grande as the border between Texas and Mexico, and Mexico recognised Texas as a part of the United States.

See also

* Battles of the Mexican-American War

Footnotes

References

* Bauer, K. Jack "The Mexican-American War 1846-48"

External links

* [http://www.mymexicanwar.com/battles/460425.htm Battle report and list of casualties]