Blood Quantum Laws are United States laws enacted to assist in defining membership in Native American tribes or nations. "Blood quantum" is the degree of ancestry for an individual of a specific racial or ethnic group. Blood quantum was first used in 1705 in Virginia to limit colnial civil rightsof peole with half or more Native ancestry.  The  Indian Reorganization Act of 1934 utilized the concept of blood qunatum to establish which individuals could be recognized as Native American. This recognition would determine eligibility for financial and other benefits under treaties or land sales.

In recent years, each Nation or tribe establishes membership basedon shared customs, traditions, language and tribal blood. This helps to preserve the unique character and traditions of each nation.  Each tribe sets forth its own enrollment criteria in their constitutions,or articlesof confederation and determines elgibility for membership. Uniform membership requirements do not exist.

Many nations have a “base roll”, or original list of members designated in their constitution or enrollment documents. The base roll is a common means of establishing membership. A person seeking enrollment in this manner must be lineally descended from someone on the base roll or have a relationship to someone descended from someone on the  base roll. Some tribal governments use blood quantum requirements, some do not. The decision is at the discretion of the tribe as part of their sovereignty. Other methods include, tribal residency, or continued contact with the tribe.

For tribes that utilize blood quantum, proper calculation is important in determining eligibility for enrollment. In tribes that do not use blood quantum as an enrollment requirement, degree of Indian blood is still used for statistical purposes and may determine the level of services an individual receives from the tribe. Some federal programs designed for the benefit of Native Americans still require a minimum blood quantum in order to be considered for services.