 Imagism influenced a number of poetry circles and <unk> the Imagists Free verse became a discipline and acquired status as a legitimate poetic form . In the 1950s , especially , with the Beat generation , the Black Mountain poets , and others associated with the San Francisco Renaissance . In his seminal 1950 essay Projective Verse , Charles Olson , the theorist of the Black Mountain group , wrote " ONE <unk> MUST <unk> AND <unk> <unk> TO A <unk> <unk> " ; his credo derived from and supplemented the Imagists . 
