Question

What was the source of conflict between the United States and Mexico before 1846?

Answer 1

Answer:

Annexation of Texas and more.

Explanation:

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).

note: you can also look this up, it is likely much faster than using brainly.