You picked the right author to explore. Dunbar's work really explores what it means to endure the hardships of being of color, and in specific terms, what it means to be African- American in American History. Try Dunbar's poem, "We Wear the Mask" as a work to reflect what it means to be the victim of discrimination that is caused by racism and slavery. Dunbar finds a balance between acknowledging the victimization that results from racism and slavery. Yet, there is a defiant mood to the poem that refuses to become a victim. In this dynamic that Dunbar articulates in the poem, there is a statement about how the African- American predicament is seen in literature. There is a validation of suffering, pain, and injustice, but a refusal to acquiesce to it. This refusal to submit and condition of perseverance helps to make such articulations such as Dunbar's voices of dissent and resistance in a cause that endures, a fight that goes on, and a belief in hope that shall never die. Examine lines such as “We smile, but, O great Christ, our cries/ To thee from tortured souls arise" or how the notion of the "mask" is what people of color were forced to wear in a society that demonstrated intolerance. The closing lines of how the mask has to be worn reflects a condition of life caused by slavery and racism that demands to be heard, a narrative that screams out that the way things are must be transformed into what should be. In this light, I think that you will be able to use the poem to reflect the themes of racism and slavery that is such a part of both your essay and what it means to be African- American as expressed through literature.