This is very interesting.

The earliest mentioning of "21st Century Skills" that I can find is in the May 13, 1968 edition of the U.S. State Department Bulletin in an article called A Joint Assault on Want (58 Dep't St. Bull. 603 (1968) 
No. 1507).

This article is very much in the same vein as most articles written by the State Department during the Cold War.  This article states that the United States must spread Democracy and freedom through the developing world by filling the "wants" of these nations--if they do not have any needs, the U.S.S.R. will not be able to step in to fill them.  The article states many initiatives to do this that include family planning, assistance with agricultural production, creating a world wide commodities market, and "the use of the transistor radio and communications satellite, which can bring 21st-century skills and education to even the most remote rural village." (Sounds similar to the role of Virtual Classes in VT)  

Anyway the article ends very interestingly...

" These constructive initiatives are the nutrients of freedom and peace. They are the things we Americans must be ready to do if we hope to keep our nation safe and free in a world of growth and change, rather than threatened and isolated in 'a world of strife. A secure world, with past differences reconciled, in which men can determine their own destinies, a world free of nuclear peril, a world without starvation and poverty, a world in control of science, not victimized by it-these are objectives worthy of a great people. Are they beyond our power to achieve?

We shall never know unless we try. And try we must, with perseverance and determination. Whether we like it or not, we live in a world so intricately interdependent that the possibility of withdrawal or isolation simply does not exist."

Rick Dustin-Eichler
Technology Curriculum Specialist
Windsor Central Supervisory Union
Woodstock, VT