As one of the federal allotment statutes enacted in the late 1800s dividing Indian reservations into individual land allotments, the Sioux allotment statute provided for Sioux lands to be held in trust by the United States. Consequently, the lands generally could not be sold or partitioned and passed to subsequent generations as undivided interests and became increasingly fractionated with each subsequent generation. On January 12, 1983, Congress enacted the Indian Land Consolidation Act (the Act) to address this problem. Section 207 of the Act barred the descent or devise of fractional interests in Indian land allotments that constituted 2 percent or less of the original allotment, requiring instead that the fractional interest escheat to the tribe. Three members of the Oglala Sioux Tribe—Mary Irving, Patrick Pumpkin Seed, and Eileen Bissonette (Sioux tribe members) (plaintiffs)—brought suit in the United States District Court for the District of South Dakota, as heirs, devisees or their representatives, against the United States Secretary of the Interior (United States) (defendant), asserting that the escheatment of 41 fractional interests under Section 207 constituted a taking of the Sioux tribe members’ property in violation of the Just Compensation Clause of the United States Constitution. The United States asserted that escheatment under Section 207 did not effect a taking because the property interests were de minimis or, alternatively, because the interests could have been conveyed inter vivos. On appeal to the Circuit Court of Appeals, the court held in favor of the Sioux tribe members. The United States appealed to the United States Supreme Court.