4. Determine the map below shows coastlines of the southeastern U. S. at three
times during the Cenozoic era. Which
choice represents the coastline at the height
of the Pleistocene ice age? Explain your
reasoning.
Choice A
Choice B
Choice C

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

The peak above is part of the  sierra madre occidentals ,  a chain of volcanic mountains that runs through the middle of central america.