The law you are referring to is the General Allotment Act of 1887, also known as the Dawes Act. The Dawes Act aimed to assimilate Native American tribes into mainstream American society by dividing tribal lands into individual allotments for Native American families. Each family was granted a plot of land, and the remaining land was opened up for non-Native settlement and development.
Under the Dawes Act, Native Americans were expected to adopt the practices and customs of white American culture. The law aimed to eliminate tribal communal land ownership and traditional Native American lifestyles in favor of private landownership and farming. The intention was to encourage Native Americans to become self-sufficient farmers and integrate them into mainstream society.
However, the Dawes Act had severe negative consequences for Native American tribes. It resulted in the loss of a significant amount of tribal land, as surplus land was sold to non-Natives. This led to the fragmentation of tribal communities, cultural disruption, and economic hardship for many Native Americans. The Dawes Act is widely criticized today for its negative impact on Native American sovereignty, culture, and land rights.