Why did Douglass choose the topic of slavery for his speech at a local fourth of July celebration?

Frederick Douglass chose the topic of slavery for his speech at the Fourth of July celebration to highlight the hypocrisy of celebrating freedom while millions remained enslaved. He aimed to awaken the conscience of his audience by contrasting the ideals of liberty and justice with the brutal reality of slavery. Douglass sought to provoke reflection on the nation's moral failures and to call for immediate action against the institution of slavery, emphasizing that true independence could not exist while such injustice persisted.