MacLean's poster made reference to the American flag in the draped bunting effect of the design, star and eagle. Headlining the Electric Flag, Moby Grape and Steve Miller split the five-day gig.
The poster was only printed once before the concert in a 5,000 print run. It measures 14" x 21".
During the early days of the Fillmore, MacLean was the most "present" member of the staff. She collected tickets, passed out handbills, blew up balloons and counted money for Fillmore productions. Impressed with her lettering skill on the upcoming attractions chalkboards, Bill Graham surprised her with an easel and art supplies for Christmas, 1967, and MacLean's poster artist career was launched. Untrained in graphic arts, MacLean's early style evolved into ornate, Medieval-Gothic designs. Faces in her posters wore trance-like stares, steady and serene, and evoke the detached spirituality of the sixties.