What was the time frame for the establishment of Native American reservations?

The establishment of Native American reservations primarily occurred during the time frame of the 1870s to the 1960s, making this the correct choice. This period marks the significant shift in U.S. policy towards Native Americans, particularly after the Civil War, where the government began to formally recognize and set aside specific lands for Native tribes. The Dawes Act of 1887, for example, aimed to assimilate Native Americans into American society by allotting them individual parcels of land, while the remaining lands would become reservations.

Throughout the late 19th and early 20th centuries, various treaties were made or reneged, which further solidified the reservation system. The Indian Reorganization Act of 1934 aimed to reverse some of the damage done by earlier policies and restore some autonomy to Native American tribes, but it also reinforced the reservation system by legally defining the areas as reservations.

While other time frames mentioned in the options do contain relevant historical events relating to Native American policies, they do not encapsulate the primary establishment of reservations as comprehensively as the chosen time frame does. The 1800s-1850s primarily focus on earlier treaties and conflicts rather than the formal reservation system, while the 1900-1950