According to the Daily Mail the shots were taken during the band's performance at Busch Stadium in St. Louis on Aug. 21, 1966. The band played in heavy rain under a makeshift shelter and the show marked one of the reasons why the group finally stopped touring.
Paul McCartney recalled:
After the gig I remember us getting in a big, empty steel-lined wagon, like a removal van. There was no furniture in there – nothing. We were sliding around trying to hold on to something, and at that moment everyone said, 'Oh, this bloody touring lark – I've had it up to here, man.'
I finally agreed. I'd been trying to say, 'Ah, touring's good and it keeps us sharp. We need touring, and musicians need to play. Keep music live.' I had held on that attitude when there were doubts, but finally I agreed with them.
According to the Mail:
The pictures were taken by Mark Richman who was the only photographer there using Kodachrome color film rather than black and white.
Mr Richman, now aged 73, stood just 12 feet (four metres) away from The Beatles to take the snaps.
He is selling them now with full copyright, meaning the new owner will legally be able to sell re-prints of them.
They are expected to fetch about $50,000 at auction.