On this day in history, April 22, 1970, the first Earth Day was
celebrated — ushering in a host of new environmental
legislation.

The idea for the observation "Earth Day" originated with Sen.
Gaylord Nelson, a Democrat from Wisconsin, who had "long
been concerned about the deteriorating environment in the
United States.”  (EarthDay.org.) 

Gaylord Anton Nelson
(June 4, 1916 – July 3, 2005)