Green’s Dictionary of Slang

boon n.2

[? SE boon companion or Fr. bon, good + poss. link to bone n.7 (1)]
(US black)

1. a close friend; also attrib.

[US]‘Ed Lacy’ Men from the Boys (1967) 31: Bill Ash had been my boon buddy for a lot of years.
[US]G. Swarthout Where the Boys Are 108: Nex’ Tuesday night my lil’ boons we go into action for causa freedom and democracy!
[US]Dahlskog Dict. Contemp. and Colloq. Usage.
[US]A. Childress Hero 22: You see me, you see him. He was my boon! [HDAS].

2. a black person.

[US] in DARE.
[US] in L. Bangs Psychotic Reactions (1988) 272: ‘All the boons just sat there laughing at me.’ ‘Boons,’ I said. ‘What’s boons?’ ‘You know [...] Black guys.’ ‘Why do you call them that?’ ‘I dunno. From “baboons”, I guess.’.
[US](con. 1970) J.M. Del Vecchio 13th Valley (1983) 86: ‘If it aint Bro Boon,’ Egan laughed [...] ‘Is that Bro Boon like in Bro Coon,’ Jax intonated with mock arrogant disgust.