Barry Finn, "If it's the same "Berta" it was collected before August Wilson was born. He couldn't have written it but he may well been familiar with the song"

Up to where the text posted above ends, it's an almost exact transcription of Berta, Berta, which Alan Lomax and Shirley Collins collected on 18.09.59 at Parchman Farm Penitentiary, Mississippi, from Leroy Miller and work gang. You can find it on Southern Journey Vol 3: 61 Highway Missisippi. Rounder CD 1703. The CD version has several more verses which appear after where the play's transcription ends.

August Wilson would have been about 15 at the time at the time it was recorded, but he probably knew the song via the original Prestige LP issues of Southern Journey which were released in the early 1960s.