In the 1930's The Mountaineers, a Seattle based recreation, education, and conservation group, first described the Ten Essentials.  In 1960 they published Mountaineering: The Freedom of the Hills, which is often termed as the standard textbook for climbing and mountaineering.  It was in this book that the Ten Essentials were learned world wide.  Throughout the years the book has been revised to keep with modern equipment and in 2007 the ten essentials were updated as well.  The essentials are now ten systems rather ten individual items as listed before (the "classic" essentials).