it was founded by united states senator gaylord nelson as an environmental teach-in first held on april 22, 1970. u thant, the secretary-general of united nations at that time, has recognized it. while the first earth day focused on the united states, the epa ( enviromental protection agency), launched by denis hayes, who was the original national coordinator in 1970, took it international in 1990 and organized events in 141 countries. its name and concept were created by john mcconnell in 1960 at a unesco conference in san francisco.