Answer:
Mexico’s claim to Texas stood in the way of American expansion to the Pacific Ocean.
Explanation:
The Mexican-American War took place from 1846 to 1848. It was largely driven by the American President James K. Polk, who sought to expand the territory of the United States to the west. It ended with the Treaty of Guadalupe Hidalgo in February 2, 1848. This treaty brought great territorial gains to the United States and the expansion of its territory to the Pacific Ocean.
Under Presidents John Quincy Adams and Andrew Jackson, the United States made two unsuccessful attempts to buy Texas from the Mexicans. When the more than 35,000 Americans living in Texas declared their independence from Mexico and declared the Republic of Texas in 1836, the Mexican government reacted violently and tried to quell the uprising. The deployment of the army failed and Texas gained independence.
In the presidential election campaign of 1844, James K. Polk stood as a candidate for the Democratic Party and was elected president with a program of a large-scale expansion policy in terms of the Manifest Destiny. Immediately after the election, he operated the annexion of Texas to the United States.
With the annexation of Texas on February 19, 1845, the claim that the Rio Grande represented both the southern and western borders passed to the United States. This situation generated an escalation that ended by starting the war on April 25th, 1846.
