Why did these powerful politicians and cultural leaders oppose the Mexican American war?

The Mexican-American War (1846-1848) was the first military war of the United States that occurred primarily on international territory. It put an economically fractured and militarily inexperienced Mexico against the US administration's expansionist-minded policy. President James K. Polk, who claimed that we had a "manifest destiny" to extend to the Atlantic across the globe. A frontier skirmish near the Rio Grande launched the war which was accompanied by several wins by the United States. As the dust settled, Mexico lost almost a third of its land, including nearly half of California, Utah, Nevada, Arizona, and New Mexico today.

Causes of the Mexican-American War

In 1836 Texas was independent of Mexico. The United States originally refused to integrate it into the Union, primarily because northern political forces resisted the creation of a modern plantation state. The Mexican government has even supported border operations and cautioned that any effort to invade would end the infighting.

Nevertheless, expansion proceedings were soon initiated following Polk's victory in 1844, and advocated for Texas to be "re-annexed" and for the Oregon Territory to be "re-occupied." Polk still had his sights on California, New Mexico and the remainder of what is currently the United States. Southeast. As his bid to buy certain lands was refused, he instigated a war by sending forces into a contested region between the Rio Grande and Nueces River that had traditionally been recognized by both countries as part of the Coahuila state of Mexico.