Native Americans, also known as American Indians, Indigenous Americans and other terms, are the indigenous peoples of the United States, except Hawaii. There are over 500 federally recognized tribes within the US, about half of which are associated with Indian reservations. The term "American Indian" excludes Native Hawaiians and some Alaska Natives, while Native Americans (as defined by the US Census) are American Indians, plus Alaska Natives of all ethnicities. Native Hawaiians are not counted as Native Americans by the US Census, instead being included in the Census grouping of "Native Hawaiian and other Pacific Islander".The ancestors of modern Native Americans arrived in what is now the United States at least 15,000 years ago, possibly much earlier, from Asia via Beringia. A vast variety of peoples, societies and cultures subsequently developed. Native Americans were greatly affected by the European colonization of the Americas, which began in 1492, and their population declined precipitously mainly due to introduced diseases as well as warfare, territorial confiscation and slavery. After the founding of the United States, many Native American peoples were subjected to warfare, removals and one-sided treaties, and they continued to suffer from discriminatory government policies into the 20th century. Since the 1960s, Native American self-determination movements have resulted in changes to the lives of Native Americans, though there are still many contemporary issues faced by Native Americans. Today, there are over five million Native Americans in the United States, 78% of whom live outside reservations.When the United States was created, established Native American tribes were generally considered semi-independent nations, as they generally lived in communities separate from British settlers. The federal government signed treaties at a government-to-government level until the Indian Appropriations Act of 1871 ended recognition of independent native nations, and started treating them as "domestic dependent nations" subject to federal law. This law did preserve the rights and privileges agreed to under the treaties, including a large degree of tribal sovereignty. For this reason, many (but not all) Native American reservations are still independent of state law and actions of tribal citizens on these reservations are subject only to tribal courts and federal law.The Indian Citizenship Act of 1924 granted U.S. citizenship to all Native Americans born in the United States who had not yet obtained it. This emptied the "Indians not taxed" category established by the United States Constitution, allowed natives to vote in state and federal elections, and extended the Fourteenth Amendment protections granted to people "subject to the jurisdiction" of the United States. However, some states continued to deny Native Americans voting rights for several decades. Bill of Rights protections do not apply to tribal governments, except for those mandated by the Indian Civil Rights Act of 1968.In 2009, an "apology to Native Peoples of the United States" was included in the defense appropriations act. It states that the U.S. "apologizes on behalf of the people of the United States to all Native Peoples for the many instances of violence, maltreatment, and neglect inflicted on Native Peoples by citizens of the United States".The census counted 248,000 Indians in 1890, 332,000 in 1930 and 334,000 in 1940, including those on and off reservations in the 48 states. Total spending on Indians averaged $38 million a year in the late 1920s, dropping to a low of $23 million in 1933, and returning to $38 million in 1940.