A U.S. state is a federated state of the United States of America that shares sovereignty with the United States federal government. Since the admission of Hawaii as a state in August 1959, there are fifty U.S. states. Because of the shared sovereignty between a U.S. state and the U.S. federal government, an American is a citizen of both the federal entity and of his or her state of domicile. Kentucky, Massachusetts, Pennsylvania, and Virginia use the official title of Commonwealth rather than State. State citizenship is flexible and no government approval is required to move between states, with the exception of paroled convicts.

The United States Constitution allocates certain powers to the federal government. It also places some limitations on the state governments. State governments are allocated power by the people (of each respective state) through their individual constitutions. By ratifying the United States Constitution, the people transferred certain limited sovereign powers to the federal government from their states. Under the Tenth Amendment, all powers not delegated to the federal government nor prohibited to the states are retained by the states or the people. Historically, the tasks of public safety (in the sense of controlling crime), public education, public health, transportation, and infrastructure have generally been considered primarily state responsibilities, although all of these now have significant federal funding and regulation as well (based largely upon the Commerce Clause, the Taxing and Spending Clause, and the Necessary and Proper Clause of the Constitution).

Indigenous peoples are ethnic groups that are defined as "indigenous" according to one of the various definitions of the term, though there is no universally accepted definition.

In the late twentieth century, the term began to be used primarily to refer to ethnic groups that have historical ties to groups that existed in a territory prior to colonization or formation of a nation state, and which normally preserve a degree of cultural and political separation from the mainstream culture and political system of the nation state within the border of which the indigenous group is located. The political sense of the term defines these groups as particularly vulnerable to exploitation and oppression by nation states. As a result, a special set of political rights in accordance with international law have been set forth by international organizations such as the United Nations, the International Labour Organization and the World Bank. The United Nations have issued a Declaration on the Rights of Indigenous Peoples to protect the collective rights of indigenous peoples to their culture, identity, language, employment, health, education and natural resources. Depending on which precise definition of "indigenous people" used, and on the census, estimates of a world total population of Indigenous people range from 220 million Indigenous peoples in 1997 to 350 million in 2004.