American expansion in the 19th century was an act of aggressive imperialism, not manifest destiny

In the years between 1830 and 1860, the United States grew economically, socially, and most noticeably, geographically. In this time period, Texas, Oregon, California, New Mexico, and Arizona were gained, completing the continental United States. Many Americans in the 19th century believed this acquisition of territory was a manifest destiny, or event accepted as inevitable. They thought it was the destiny of the U.S. to control all land from the east coast to the west coast. However, I believe that this land was taken as an act of aggressive imperialism on the part of the United States. I…