Native Americans in the United States is the phrase that describes indigenous peoples from North America now encompassed by the continental United States, including parts of Alaska and the island state of Hawaii. They comprise a large number of distinct tribes, states, and ethnic groups, many of which survive as intact political communities. http://en.wikipedia.org/wiki/Native_Americans_in_the_United_States

Private foundations are legal entities set up by an individual, a family or a group of individuals, for a purpose such as philanthropy. The Bill & Melinda Gates Foundation is an example of a private foundation. Various countries have laws relating to the establishment and operation of these foundations. Unlike a charitable foundation, a private foundation does not solicit funds from the public.

http://en.wikipedia.org/wiki/Private_foundation

501(c) is a provision of the United States Internal Revenue Code (26 U.S.C. § 501(c)), listing twenty-eight types of non-profit organizations exempt from some Federal income taxes. Sections 503 through 505 list the requirements for attaining such exemptions. Many states reference Section 501(c) for definitions of organizations exempt from state taxation as well. - Wikipedia at: http://en.wikipedia.org/wiki/501%28c%29