Mexican-American War:Manifest Larceny

"I want Mexico next!"

In 1844, James Polk became POTUS while running on a strong "Manifest Destiny/ Expansion" platform which called for the annexation of California and Texas. As soon as Texas was granted statehood (December 29, 1845), Mexico broke off diplomatic relations with the United States and prepared for a potential war with the United States.



Almost immediately, the perfect pretext for this war began...a boundary dispute. For decades, in Spanish and Mexican History the western border of Texas Territory was the Nueces River. But in 1836, the Republic of Texas claimed the Rio Grande River as it's new boundary (a difference of millions of acres) based on a verbal surrender agreement with Santa Anna.  However, this verbal agreement was never recognized or legally ratified by the Mexican government.

Zach Taylor's Troops Camp on the Nueces

President Polk (July 8, 1845) ordered General Zachary Taylor and 4,000 troops into the disputed area...

"The assembling of a large Mexican Army on the borders of Texas , and crossing the Rio Grande with a considerable force will be regarded as an invasion of the United States and the commencement of hostilities...you may in your discretion cross the Rio Grande, disperse or capture the forces assembled to invade Texas, defeat the junction of troops uniting in that purpose, drive them from their positions on either side of the river, and, if deemed practicable and expedient, take and hold possession of other places in the country (Mexico).

General Taylor (October 4, 1845) wrote back to Washington, D.C....

"Mexico having as yet made no positive declaration of war, or committed any overt act of hostilities, I do not feel at liberty under my instructions...to make a forward movement."

On January 13, 1846, orders were sent to Taylor ordering him to provoke Mexico into war.

Mexican General Pedro Ampudia complained to General Taylor in a letter...

"Your advances on the Rio Grande have not only insulted but exasperated the Mexican nation...If you insist on remaining upon the soil of the department of Tamaulipas (Mexican Territory), it will clearly result that arms, and arms alone, must decide the question."

In April of 1846, hostilities erupted and Polk had his war.  General Taylor announces success in the provocation of Mexico...

"Hostilities may now be considered as commenced."

And that is how to start a war...thank goodness we've never done that before!