The National Inventors Hall of Fame (NIHF) is an American not-for-profit organization which recognizes individual engineers and inventors who hold a U.S. patent of highly significant technology. Founded in 1973, its primary mission is to "honor the people responsible for the great technological advances that make human, social and economic progress possible." Besides the Hall of Fame, it also operates a museum in Alexandria, Virginia, and a former middle school in Akron, Ohio, and sponsors educational programs, a collegiate competition, and special projects all over the United States to encourage creativity among students. As of 2020, 603 inventors have been inducted, mostly constituting historic persons from the past three centuries, but including about 100 living inductees. An NIHF committee chooses an annual inductee class in February from nominations accepted from all sources. Nominees must hold a U.S. patent of significant contribution to the U.S. welfare, and which advances science and useful arts. The 2020 class included 22 inventors.