The "Age of Aquarius" is captured for all time in Czech director Milos Forman's version of the hit 1960s Broadway musical. A clean-cut midwestern kid named Claude (John Savage), fresh off the bus from Oklahoma and eager to do service in the military, comes to New York and ends up sidetracked by a nomadic tribe of hippies in Central Park.

The group is vibrantly led by Berger (Treat Williams). Claude is eventually assimilated into this family of protesters and falls in love with Sheila, a girl from a wealthy family. Their happiness is cut short when Claude has to report for duty in the Vietnam War. The plot hangs in the balance when Berger poses as Claude to buy Claude a little more time in the name of love.

The film is notable for its hit songs such as "Let the Sun Shine In," its choreography by Twyla Tharp, a cameo by the late Nicholas Ray as a general, and for jump-starting the careers of Treat Williams and Beverly D'Angelo. The screenplay by Michael Weller, based on the musical by Gerome Ragni and James Rado, with music by Galt Macdermot, effectively captures the feeling of the movement.