Question

The annexation of Texas in 1845 broke off peaceful ties between the United States and Mexico. The two nations were soon locked into a border dispute that burst into a war. The United States claimed the border lay at the . However, Mexico insisted that the border lay 100 miles farther north.

Answer 1

Answer:

Following Texas' successful war of independence against Mexico in 1836, President Martin van Buren refrained from annexing Texas after the Mexicans threatened war. ... His efforts culminated on April 12 in a Treaty of Annexation, an event that caused Mexico to sever diplomatic relations with United States.

The Mexican-American War was a conflict between the United States and Mexico, fought from April 1846 to February 1848. ... 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).