Mr. Clay was never a slave, he might have picked cotton, chopped cotton, or hung tobacco for wages but doubt it. He wouldn't even submit to the draft, so tell me how can you call Cassius Clay a slave name.
Cassius Marcellus Clay Sr. was named after Cassius Marcellus Clay, a white abolitionist. Mr. Clay Sr. was apparently proud enough of the name to pass it on, so tell me why was Cassius Clay considered a slave name.