Why do Indian Tribes in the US have Casinos?
Indian Tribes are sovereign nations. They have governmental relationships with the Federal and State Governments that is similar to the relationships between the US and France for example. In the late 70’s the Indian nations started to put some forms of gambling on their reservations and by the mid 1980’s they had full fledged gambling.
In 1987 the famous Cabazon case in the US Supreme court held that the Indian Tribes had the right to have gaming on their reservations. The Indian Gaming Regulatory Act was quickly passed by the US Congress to limit Tribal Gaming. The IGRA still governs Tribal Gaming and imposes regulations and restrictions on what gaming can occur under what conditions. For the most part Tribes have to enter into compacts with the States that they are located in.
To learn more about this, two main resources are the National Indian Gaming Association, and the National Indian Gaming Commission.
Tribal Gaming is highly regulated by Tribes, the States (in somecases) and the Federal Government.