What philosophy meant that the United States set apart to extend its boundaries all the way to the pacific?

The philosophy for expansion by the US government to expand to the Pacific to form one great country was known as Manifest Destiny. It included the encouraged movement of large numbers of people to move West. It also included the building of many railroads to link the different areas of the new west to the east.

The downside was that it destroyed the native americans way of life and forced them onto reservations.