The Trail of Tears
Millions of acres of American Indian ancestral land (in Georgia, Tennessee, Alabama, North Carolina and Florida) was stolen by the Federal Government. The reason? So that white settlers could move in and use the land for their advantage in such endeavors as growing cotton.
The removal of native people from their lands and homes of many generations began in the early 1830s, when nearly 125,000 Native Americans began their tragic journey known as the Trail of Tears. They were sent to live in Indian Territory what eventually would become the state of Oklahoma. Oklahoma meaning: “red people”. The translation is from the Choctaw Indian words okla and humma.
Source: http://www.history.com/topics/native-american-history/trail-of-tears