A border dispute sparked by the US annexation of Texas in 1845 soon led to all-out war between the two countries. Under the terms of the Treaty of Guadalupe Hidalgo that ended the war, Mexico confirmed US claims to Texas and ceded lands constituting present-day California, Nevada, and Utah, and parts of Arizona, New Mexico, Colorado, and Wyoming in exchange for an indemnity of $15 million and US assumption of American claims against Mexico. How did the US’s victory precipitate its Civil War? Discuss