From the 1820s to the 1860s, Americans began to expand westward beyond the Mississippi River. Americans were beginning to move west of the Mississippi River without any consent of the government, and many of the them were moving for their own personally reasons such as to start a new life or he/she wanted to be a pioneer in a newfound area. The federal government played a mostly passive role in the American expansion, but the United States government intervened in some areas more than others. For instance, the U.S. government clearly set its standards for the Oregon Territory ever since Gray’s expedition. People moving west had both positive and negative impacts on the country as a whole. However, Native Americans were deeply impacted by people
