So the mayor of New York shut down 5th Avenue for a couple of hours on April 22, 1970, and had actors Paul Newman and Ali MacGraw address the multitudes there. Big deal — Philly's original Earth Day was the real place to be. It was so big that it spread out over a week leading up to Earth Day. No city topped it.

Edward Furia, project director of "Earth Week 1970," compared the New York observance to Philly's: "It was just a parade to them. Our activity was clearly the biggest in the country IF you're counting people who know what's going on."

No Newman or MacGraw, but we had Maine Sen. Edmund Muskie, author of the Clean Air Act, as well as Ralph Nader, Paul "Population Bomb" Ehrlich, Lewis Mumford, Allen Ginsberg, Frank Herbert ("Dune"), the entire Broadway cast of "Hair" and countless environmental and urban planning legends.

Speaking of legends, one Earth Day participant who can't go unmentioned is convicted murderer Ira Einhorn, at the time a hippie guru who wanted to be in on "Earth Week." As Furia tells it, Einhorn kept crashing their planning meetings and they finally took him up on an offer to line up Ginsberg if he, Einhorn, could introduce the poet.

On April 22 the weather was beautiful and even more people showed up in Fairmount Park than had been at the previous night's event on Independence Mall. Furia and Earth Day chairman Austan Librach picked up Muskie from the airport and by the time they returned to the venue, Einhorn was up on stage dancing — "well, sort of dancing," Furia said — to the Native American band Redbone and tossing out emcee-style asides.

Furia and Librach went onstage and asked Einhorn to leave, as Muskie was due to speak and the PBS cameras were waiting to cut over for their Philadelphia segment. "And Ira says, 'Muskie's not gonna get the live TV coverage — Redbone is!'"

Muskie calmed the organizers' fears, saying PBS would just cut over when he started his keynote speech, and suggested waiting till "the hippie guy" got tired.

After nearly a half-hour of this, Furia said, he could tell the crowd was beginning to grow weary of Redbone, "great band, but kind of one-note, you know?" and he suggested to Einhorn that they could forcibly remove him. "Ira says, 'You see all these kids? They're mine. You take me off and you've got a riot.' Now, I was in a suit with short, combed hair, as was Austan [Librach], and this guy is in beads with his hair going down his back — how would that look? It didn't seem like an idle threat."

Finally Einhorn ceded the stage to Muskie, but only after grabbing the senator and giving him a kiss "smack on the mouth — a big juicy one," Furia said. Despite Muskie's legendary temper, he calmly removed his handkerchief, wiped his mouth off, stepped around the interloper and began his speech. "Meanwhile Ira beats a hasty retreat and disappears for the rest of the day."

Later, however, when he became a fugitive in his girlfriend's murder,Einhorn's recollection of this incident expanded to him "giving the keynote address" at Earth Day, and he retroactively named himself "the founder" of Earth Day.

It was partially to set and keep the record of Philly's Earth Week 1970 straight that its actual founders put together a new Web site, earthweek.us. There you can get the basic background on how this huge project came together after a suggestion by Wisconsin Sen. Gaylord Nelson, browse historic photos, listen to the music played, and watch the hour-long CBS report, one-third of which is devoted to Philadelphia.

Earth Day 1970 had a big impact on the lives of most of its attendees (Furia went on to head the mid-Atlantic chapter of the newly-created Environmental Protection Agency) and on public policy. But it's questionable whether a single event in our current era could be so transformative.

Live Earth, a global series of simultaneous concerts in 2007, strove to achieve that, but ended up a pale shadow. The aim of the 1970 organizers was to bring "ecology" into the mainstream, and a key target was the proliferation of Agent Orange (a defoliant that turned out to be harmful to people as well as plants), marketed by Dow Chemical. Live Earth has a much more fractured focus, and one of the organization's partners in saving the planet is, yes, Dow Chemical. Oh, the times, they have a-changed. *

— Vance Lehmkuhl

Thanks to Neil Benson for assistance in preparing this story.