The Art of Harlem renaissance was optimistic because first and foremost it promotes African American achievements. By this art, they cans how the world how artistic and talented African American are in terms of literary, musical, performing arts and visual.
Second reason, is they were able to show the life of the black Americans. By this, people will able to know the life that African American gone through and how they fought for it. It serves as new opportunity for the African and a new start.