Answer:
The Mexican-American War was a conflict that confronted Mexico and the United States between 1846 and 1848. It was the first war that both nations had against a foreign country after their respective independence and began as a result of the expansionist pretensions of the United States, whose first step was the creation of the Republic of Texas, which separated from the Mexican state of Coahuila and Texas. Other triggers were the entry of the US Army into the area between the Nueces and Rio Grande rivers and the demand for compensation from the Mexican government for the damages caused in Texas during its war of independence.
The Americans landed in Veracruz and conquered the Mexican capital, after which the Mexicans were forced to sign the Treaty of Guadalupe Hidalgo, by which the United States annexed the current states of California, New Mexico, Arizona, Nevada, Utah, Colorado and part of today Wyoming.
