Answer:
Louisiana purchase on April 30, 1803, Texas annexation on December 29, 1845, Gadsden Purchase on December 30, 1853, Mexican Cession on February 2, 1848, and the Adam-Onis Treaty on February 22, 1821
Much more mixed cultures eg brazil. industrilisation of most cultures who used slavery through cheap labour that benifited the society eg russia but also at a great cost usually death disease and social unrest
Because it expressed the fact that Americans didn't want European countries that had economic or colonists interests to put a foot in the United States.
