While the history of Indian/Settlor relations pre-dates the creation of the United States, primary U.S. resources begin with the United States Constitution:
United States Constitution, Art. 1, § 8 "The Congress shall have Power To regulate Commerce with foreign nations, and among the several States, and with the Indian Tribes..."
Congressional Representation: Article 1 "Representatives...shall be apportioned among the several States...according to their respective Numbers, which shall be determined by adding to the whole Number of free Persons,...excluding Indians not taxed, three fifths of all other Persons."
Amendment XIV - Section 2: "Representatives shall be apportioned among the several States according to their respective numbers, counting the whole number of persons in each State, excluding Indians not taxes." (1868)
In addition, primary U.S. resources include the United States Code: Title 25 - Indians and Title 18 Crimes and Criminal Procedure The Major Crimes Act - 18 U.S.C. §1153 (see also, Titles 5, 28, and 42).
You may also refer to the Senate Committee on Indian Affairs: Senate Indian Affairs Committee.
The Marshall Trilogy
Johnson v. M'Intosh, 21 U.S. 543 (1823)
Cherokee Nation v. Georgia, 30 U.S. 1 (1831)
Worcester v. Georgia, 31 U.S. 515 (1832)
The General Allotment Act (1887) (The "Dawes" Act)
Lone Wolf v. Hitchcock, 187 U.S. 553 (1903)
Winters v. U.S., 207 U.S. 564 (1908)
Indian Citizenship Act (1924)
The Indian Reorganization Act (1934) (HeinOnline)
House Concurrent Resolution 108 (1953) (FDsys, HeinOnline)
Public Law 280 (1953) (FDsys, HeinOnline)
Urban Relocations Program
Navajo-Hopi Rehabilitation Act of 1950 (FDsys, HeinOnline)
Indian Relocation Act of 1956 (FDsys, HeinOnline)
Indian Self-Determination and Education Assistance Act (1975) (FDsys, HeinOnline)
Indian Civil Rights Act (1968) (FDsys, HeinOnline)
Indian Child Welfare Act (1978) "ICWA" 25 U.S.C. ss 1901 et seq. (FDsys, HeinOnline)
American Indian Religious Freedom Act (1978) (FDsys, HeinOnline)
Native American Graves Protection and Repatriation Act (1990) (FDsys, HeinOnline)
Tribal Law and Order Act (FDsys, HeinOnline)
Violence Against Women Act (1994) (FDsys, HeinOnline)