Frederick Douglass employs parallelism in his speech to create a rhythmic and powerful rhetoric that emphasizes his condemnation of the hypocrisy surrounding the celebration of American independence in the context of slavery. By using parallel structure, he underscores the contrasts between the proclaimed values of freedom, liberty, and equality and the reality experienced by enslaved people.
The repetition of similar grammatical structures in phrases like "your celebration is a sham," "your boasted liberty, an unholy license," and "your shouts of liberty and equality, hollow mockery" enhances the emotional impact of his message. This technique captures the attention of the audience, drives home the severity of his critiques, and reinforces the moral urgency of his argument.
Furthermore, the use of parallelism helps to unify his points, making them more memorable and compelling. It allows Douglass to construct a systematic dismantling of the celebratory narrative of American freedom, showing that the very elements that are lauded in society are in stark contrast to the lived experience of enslaved individuals, thus creating a profound sense of injustice and calling for a reevaluation of American values.