Which correctly describes a reason the united states declared war on mexico in 1846?
a.
the hope of freeing texas from mexican rule
b.
the concept of manifest destiny through expansion
c.
the issue of mexico's slave-based economy
d.
the desire to annex the oregon territory

The correct answer is B. the concept of Manifest Destiny through expansion. The US believed that it was their destiny to spread all the way to the western shores so they naturally wanted to annex Texas and New Mexico as well. They also wanted California and Oregon Country which would ensure that they are spread from coast to coast.