I was figuring out what to say about Emperor Joneswhen I came across Edward L. Shaughnessy's essay "O'Niell's African and Irish-Americans: stereotypes or 'faithful realism'?". According to him, O'Niell "achieves whatever universality his art my claim":
Accepting Nietzsche's "death-of-God" proclamation, the playwright nevertheless sought to invest his characters with a dignity denied by the narrow assumptions of the prevailing literary naturalism. (Indeed, he once proposed to call his work "supernaturalism.") All persons, without regard to the accidents of birth (place, endowment, and race), suffer the ineluctable condition of humanity: the tragedy of time. In this sense O'Niell is more concerned with "fate" than with determinism. Therefore, his major black plays finally deal less with racial matters than with the more fundamental question of what it means to be human.
Beyond what one might consider stereotypically black about Emperor Jones(the manner of speech, most crucially), it is most important to consider how Jones breaks out of the stereotype of the subservient and submissive black slave. He is armed with agency (or, freedom of movement), with political power (of which he is stripped, but seeks to regain) and with the power to kill (his armed gun). It is not his racial situation that entraps him, but his ego; he is not killed out of folly but out of guilt. O'Niell's assertion that his work is "supernaturalist" depicts him as a playwright more concerned with the tragedy of one's habits and actions - transcending the typically naturalistic point of view that one's fate is determined by wat has been given/endowed/provided at birth. (On the flip side, one might say that Jones' death is brought about because Jones aspired to a position of power as Emperor he was never destined to have.)