The annexation of Texas as a US state in 1846 directly led to the war, but US ambitions toward the Mexican lands in the West were the driving force for the conflict.
American presidents John Tyler (term 1841-1845) and James K. Polk (term 1845-1849) wished to extend the US territories to the Pacific coast and consolidate what they saw as the "Manifest Destiny" of the country. US interests had expanded in California and its leaders sought to acquire it by any means necessary. The American settlers in Texas had already split off from Mexico and established a republic since 1836. Its annexation as a US state in 1846 led to border conflicts that quickly escalated into war.
Background to the war
When Mexico won its independence from Spain in 1821, the territories it possessed included Mexico, most of Central America (Guatemala, El Salvador, Honduras, Nicaragua and Costa Rica) as well as today's US States of California, Nevada, Utah, Texas and parts of Colorado, Arizona, New Mexico, and Wyoming.
Due to the extremely low population for such territorial extension (estimated at only 12 million in 1824), Mexico relaxed its Immigration policies and allowed American settlers to help populate the northern territories. The conditions to settle were simple: 1) to pledge allegiance to Mexico and 2) observe Mexican laws and customs. In 1830, these laws incorporated the banning of slavery. As many American settlers in such territories were slave owners, they looked for a pretext to secede from Mexican control.
In 1835, Mexican President Antonio Lopez de Santa Anna took measures to transform Mexico from a Federal Republic to a Centralist Republic. This move prompted both Yucatan and Texas to secede from Mexico. Santa Anna's government invaded both regions. While Yucatan was regained, Texas defeated Santa Anna and his armies and became a separate republic in 1836. As is the case with today's mainland China and Taiwan, Mexico saw Texas as a rebellious province to be reincorporated at a later time -- preferably by diplomatic means, but by force if necessary. The Mexican government warned the United States that annexation would mean war.
Texas Annexation
By this time, US President John Tyler had learned of California and its riches. In a letter to Tyler, American Plenipotentiary Minister in Mexico, Waddy Thompson, Jr. wrote :
"As to Texas I regard it as of very little value compared with California, the richest, the most beautiful and the healthiest country in the world... with the acquisition of Upper California we should have the same ascendancy on the Pacific... France and England both have had their eyes upon it."
Tyler believed in Manifest Destiny, a term which meant the annexation of all North America into the United States. He didn't believe in Texas but coveted the other territories west of Louisiana, California being the "Crown Jewel". He eventually pushed for annexation of Texas, offering it admission to the Union on March 1, 1845. His successor, President James K. Polk, ratified the admission on December 29 of that year. These moves had much potential to lead to war with Mexico, and ultimately did so.
The War Begins
Faced with the likelihood that Texas would be lost forever, the Mexican government deposed its president and refused to negotiate with US envoy John Slidell, who had been sent to broker a purchase of the lands. When a US patrol was attacked between the Nueces and Rio Grande Rivers, the US declared war on Mexico, on May 13, 1846. But the first major battles had already taken place between May 3 and 9 at Fort Texas and at Brownsville on the Rio Grande.
The Manifest Destiny, and disputes over the Texas border
Border disputes and the US annexation of Texas.
Mexico refused to negotiate the sale of Alta California and Nuevo Mexico, the annexation of Texas and the Thornton Affair.
The US annexation of Texas and the Thornton Affair.
Texas Annexation and Boundry's
Conflict over territory.
States Rights and slavery (human rights) are two causes.
Ineffective military tactics of The Schlieffen Plan, and new tactics needed for trench warfare were the main reasons behind the stalemate.
Mexican American War
Well the war that caused the proclamation of 1763 was the French and Indian war
it caused the civil war it caused the civil war
Japan's move on war.
So many people have different reasons why WW1 was caused, but the main reason was that someone killed the prince. Some other reasons are because of nationalism, imperialism, and militarism.
World War 1 was caused by two terrorists. World War 2 was caused by some Fanatics.
States Rights and slavery (human rights) are two causes.
Inflation made supplies more expensive
Inflation made supplies more expensive (Apex)
It's causes can be tracked back to tensions that formed early in the nations history.
Hitler caused WW2 had nothing to do with the treaty Hitler never mentioned it in any of his Rants
because the get shot
obviously not me!!
They were thinking of the children
well to strat with the revolutionary war was a war caused mainly by the French and Indian war. England or back then called Great Britain won the war. they won the war but lost a good deal of money. so the Parliament of Britain passed tax laws. this made colonists angry.in which caused them to go to war with Britain. so i guess if there was no French and Indian war (also known as the 7 years war) history might have been different.