American Indian Tribes are recognized in federal law as possessing sovereignty over their members and their territory. Sovereignty means that tribes have the power to make and enforce laws, and to establish courts and other forums for resolution of disputes. The sovereignty that American Indian Tribes posses is inherent, which means that it comes from within the tribe itself and existed before the founding of the United States. Tribal sovereignty is not absolute, but rather is subject to certain limits resulting from the unique relationship of the tribes to the United States. Under federal law, tribes are said to retain all those aspects of their original sovereignty except aspects that have been given up in a treaty, taken away by an act of Congress, or divested by implication as a result of their dependent status. In addition to inherent sovereignty, tribal governments may also exercise authority delegated to them by Congress.