Live 8 exploded on to the stage in Philadelphia with a rousing performance by the Kaiser Chiefs, beamed live straight to Hyde Park.
Footage from Live 8 events taking place all over the world was shown before Sir Paul McCartney and U2’s rendition of Sergeant Pepper flooded the screen.
Bob Geldof’s image sent the crowd wild as he welcomed America to the party.
The cheers only got louder as the host of the show took to the stage.
“My name is Will Smith and right now you are watching the biggest global event that has ever taken place in the history of our planet,” he said.
“Bigger than the Superbowl, and bigger than the Olympics.”
An estimated 500,000 people crowded the streets before the Philadelphia Museum of Art to witness the historic event and echo the same message of 20 years ago.
The screams subsided to a hush as Smith asked everyone to click their fingers in time every three seconds to represent the thousands that are dying in Africa every day.
He said he was honoured to share the stage with an original copy of America’s Declaration of Independence.
“Today this is a declaration of Inter-Dependent,” he said. “We are all in this together.”
The Black Eyed Peas then stormed the stage for a blinding rendition of Where Is The Love.
Earlier, the One campaign behind the event begged President George Bush to hear what was being said and act onit.
Comic actor Chris Tucker said if G8 leaders paid attention, today could change the world.
“We want them to know that we want this to happen,” he said. “We want to save lives.”
A spokesman said that what was before the world today was the one chance to make a difference in this generation.
“This chance will go on, it does not end here. This is where it begins,” he said.