Its all relative on how you would consider justification. The 19th century Americans had the idea of Manifest Destiny, like it was there "Destiny" to expand westward and take over most of the continent. But, as you probably know, there were already people living there (natives.) The Native Americans were already pushed westward and put on reservations to try to "civilize" them. But once again, it is all relative.
The U.S. Canadian border
The US propaganda that expanding the US border all the way to the Pacific Ocean was the country's "destiny". There is nothing to support this silly idea other than to justify taking what isn't yours.
yes...
yes...
russia is the closest country and it does not touch the border of the US!!! :)
The US does not border Finland or Andorra.
when did the US close the border beween Mexico and the US
The two countries that border the US is Canda (to the north of the US), and Mexico (to the south of the US).
Many Americans felt justified in expanding U.S. influence due to a belief in Manifest Destiny, the idea that it was the nation's divine right and destiny to expand across the continent. This sentiment was fueled by a sense of cultural superiority, as many viewed American democracy and capitalism as models for the world. Additionally, economic interests and the desire for new markets and resources motivated expansionist policies, reinforcing the perception that spreading U.S. influence was beneficial not only for America but also for other nations.
yes
yes
It was for control.