Answer: The history of relations between Native Americans and the federal government of the United States has been fraught. To many Native Americans, the history of European settlement has been a history of wary welcoming, followed by opposition, defeat, near-extinction, and, now, a renaissance. To Europeans and Americans, it has included everything from treatment of Native American nations as equals (or near-equals) to assimilation to exile to near-genocide, often simultaneously.
Late 18th Century
Many Native American tribes allied with the British during the Revolutionary War. However, the Treaty of Paris, which ended the war, was silent on the fates of these British allies. The new United States government was thus free to acquire Native American lands by treaty or force. Resistance from the tribes stopped the encroachment of settlers, at least for a while.
Treaty-making
After the Revolutionary War, the United States maintained the British policy of treaty-making with the Native American tribes. In general, the treaties were to define the boundaries of Native American lands and to compensate for the taking of lands. Often, however, the treaties were not ratified by the Senate, and thus were not necessarily deemed enforceable by the U.S. government, leaving issues unresolved.
On occasion, the representatives of Native American tribes who signed the treaties were not necessarily authorized under tribal law to do so. For example, William McIntosh, chief of the Muskogee-Creek Nation, was assassinated for signing the Treaty of Indian Springs in violation of Creek law.
Treaty-making as a whole ended in 1871, when Congress ceased to recognize the tribes as entities capable of making treaties. The value of the treaties also came to be called into question when the Supreme Court decided, in 1903, Congress had full power over Native American affairs, and could override treaties. Many of the treaties made before then, however, remained in force at least to some extent, and the Supreme Court was occasionally asked to interpret them.
One notable treaty with ongoing repercussions is the Treaty of Fort Laramie of 1868. Under that treaty, the United States pledged, among other things, that the Great Sioux [Lakota] Reservation, including the Black Hills, would be "set apart for the absolute and undisturbed use and occupation" of the Lakota Nation.