Formally known as the AFI's 100 Years... 100 Movies, the AFI Top 100 Films List was the first installment in AFI's 100 Years...Series, that attempted to list the greatest American movies in a wide variety of categories. This highly controversial list, first unveiled in 1998, attempted to collect the greatest American movies of all time. Films were chosen based on seven key criteria of being feature length (40 minutes or longer), American made, attracting critical recognition, having won major awards, demonstrating popularity over time, possessing a historical significance, and having a cultural impact. In 2007 the AFI released an updated version of the list, with 23 films changed from the original.