The-crowd-at-Earth-Day-Philadelphia2-web CROP.jpg

A view from the stage for Earth Day April 22, 1970, in Fairmount Park in Philadelphia. An estimated 20,000 to 40,000 people attended the event, part of the city's Earth Week. (1970 Earth Week Committee of Philadelphia)
A view from the stage for Earth Day April 22, 1970, in Fairmount Park in Philadelphia. An estimated 20,000 to 40,000 people attended the event, part of the city's Earth Week. (1970 Earth Week Committee of Philadelphia)