USA HISTORY

Detailed explanation-1: -It stemmed from the annexation of the Republic of Texas by the U.S. in 1845 and from a dispute over whether Texas ended at the Nueces River (the Mexican claim) or the Rio Grande (the U.S. claim).

Detailed explanation-2: -Polk had accused Mexican troops of having attacked Americans on U.S. soil, north of the Rio Grande. But Mexico claimed this land as its own territory and accused the American military of having invaded.

Detailed explanation-3: -The immediate cause of the Mexican-American War was a disputed boundary between the United States and Texas on the Nueces Strip. Mexico did not recognize Texas as legitimate American territory and Texas admission to the United States antagonized Mexican officials and citizens.

Detailed explanation-4: -He sent an American diplomat, John Slidell, to Mexico City to offer $30 million for it. But the Mexican government refused to even meet with Slidell. Polk grew frustrated. Determined to acquire the land, he sent American troops to Texas in January of 1846 to provoke the Mexicans into war.

Detailed explanation-5: -In late April 1846, Mexican troops crossed the Rio Grande and killed eleven U.S. soldiers. In response, Polk requested a declaration of war from Congress, arguing that Mexicans had “shed the blood of our fellow-citizens on our own soil.” By May 13, 1846, both nations officially were at war.