Manifest Destiny has been cited as often being the motivatio

Solution

it means that exploring and spreading US culture, system in all the areas of legal, political, economical and even social aspects also. simply it can be say as  that the destiny of the U.S. to expand its territory over the whole of North America and to extend and enhance its political, social, and economic influences.

the main reasons which they say to others are: the special virtues of the American people and their institutions, America\'s mission to redeem and remake the west in the image of agrarian America and irresistible destiny to accomplish this essential duty.

it can be say as Americazation, and it is not good. on this planet, every place has its own and uniqe nature, style, climate and culture. one should understand it and should follow it. should not make everything as artificial and change it according to people greeds.