 <unk> influenced a number of poetry circles and <unk> the <unk> 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 <unk> Verse , Charles <unk> , the theorist of the Black Mountain group , wrote " <unk> <unk> <unk> <unk> <unk> <unk> <unk> <unk> A <unk> <unk> " ; his <unk> derived from and supplemented the <unk> . 
