Define escarpments

A) Long stretches of savanna

B) high elevation plateaus, found mainly in alpine regions

C) Barrier mountains that mark desert edges

D) Steep jagged cliffs that mark the edges of plateaus

It is the doctrine that the us had the right and duty to expand throughout north america. it just means they believed they had the right to expand westward and they did! they stated with the 13 colonies and then they kept moving gaining different territories throughout the years