The Mexican Cession and the Treaty of Guadalupe Hidalgo.
They didn't; that is the reason they declared war on Mexico. See related questions.
a Mexican soldier would face many difficulties. like family loss, starvation, lice & ticks, fallen comrades. many thing, thay would even try to live off the land.
The United States annexed new territory in former Mexico, and the Mexican government did not recognize it. Eventually, it came to violence until US forces captured the Mexican capital and forced them to surrender and agree to US terms.
Northeastern United States.
Northern abolitionists.
yes.
Texas and Mexico did not agree about Texas boundrys
The 1810 Mexican war was a fight for Mexican independence from Spain. The 1910 was a revolution or struggle between the Mexican government and the Mexican people.
Bring the Mexican government to the bargaining table.
Yes.
war
they couldn't agree to have guacamole or salsa on cinco de mayo