The central symbol of the poem is the mule. This figure defines all of the thematic arguments the speaker presents. Traditionally, mules are domesticated animals used for heavy labor. They are an unnatural creature—the hybrid result of mating a male donkey and a female horse, which only occurs when forcibly created by people. In the popular imagination, mules are obstinate creatures (the word is used as a human insult)—a trait that the poem valorizes and reimagines as determination and insistence in the face of mistreatment. No matter how hard the mule’s life is, the speaker only sees it grin, relentlessly demonstrating its inner humanity and intellectual life. This quality makes the mule a powerful symbol in Hughes’s poem. By comparing Black people to the mule, Hughes comments upon the dehumanization of African Americans through slavery and forced labor, and also gives hope that they can persevere in reclaiming their selfhood, agency, and status.

Although the mule is itself a symbol for Black people and their socially limited position in 1940s US society, Hughes adds dimension to the comparison with a surprising description: The mule has “gota grin on his face” (Line 2). The grin changes and complicates the symbol of the mule in a highly specific way.