Atlantic City Pop Festival
The Atlantic City Pop Festival took place in 1969 on August 1, 2 and 3rd at the Atlantic City race track, two weeks before Woodstock Festival. It actually took place in Hamilton Township at the Atlantic City Race Course. There was heavy security at the festival, and the stage the acts performed on was created by Buckminster Fuller. A ticket for the entire 3-day weekend was $15.00 to see all of the performers listed. Attended by some 100,000+ people. Performers
The festival featured the following performers:

Aum
Booker T. & the M.G. 's
Tim Buckley
Paul Butterfield Blues Band
The Byrds
Canned Heat
The Chambers Brothers 
Chicago (as the Chicago Transit Authority)
Joe Cocker
The Crazy World of Arthur Brown
Creedence Clearwater Revival
Crosby, Stills & Nash (billed, but did not perform)
Cass Elliot
Iron Butterfly
Jefferson Airplane
Dr. John the Night Tripper 
Janis Joplin
B.B. King
Lighthouse
Little Richard
Looking Glass  
Lothar and the Hand People
Mississippi Fred McDowell
Hugh Masekela
Buddy Miles
Joni Mitchell
The Mothers of Invention
Tracy Nelson & Mother Earth
Procol Harum
Buddy Rich
Biff Rose
Santana
Sir Douglas Quintet
Three Dog Night
The American Dream
Johnny Winter (billed, but did not perform)

Highlights
Lineup changes:
The Moody Blues were scheduled but the band did not appear. Blues guitarist Johnny Winter was present but unable to perform because of equipment trouble. Janis Joplin and Mama Cass introduced Santana as their favorite band; this was their first appearance on the East Coast. See also
List of historic rock festivals
List of music festivals in the United States

References

1969 in New Jersey
Hippie movement
Rock festivals in the United States
Folk festivals in the United States
Music festivals established in 1969
Pop music festivals in the United States
1969 music festivals