Middlesex 235BisIV, Political and Social Series (Dalton & Hamer, page 542)

Denomination: penny
235BisIV.  O: Chained Negro in supplication. AM I NOT A MAN AND A BROTHER.
              The legend in smaller letters. Similar to No. 235. There is
              a difference in the ground, and a ? at the end of legend.
           R: WHATSOEVER | YE WOULD THAT | MEN SHOULD DO | TO YOU, DO YE |
              EVEN SO TO | THEM. The period further from M. Same as 
              No. 235BisI.

In Addenda, page 542.

Keywords

am i not a man and a brother,whatsoever ye would that men should do to you do ye even so to them