Final answer:
The author is Langston Hughes, who was a crucial figure in the Harlem Renaissance and celebrated African-American culture in his writings.
Step-by-step explanation:
The author in question, who was the son of former slaves, and by the time of his death had written four novels, four collections of short stories, more than ten volumes of poetry, and several musicals, is Langston Hughes. A central figure in the Harlem Renaissance, Hughes was renowned for his literary work that celebrated African-American culture and addressed issues such as racism and marginalization. Langston Hughes' notable poems include 'The Negro Speaks of Rivers' and 'I Too, Sing America,' where he emphasized the dignity and resilience of the African-American spirit. His writing was influential in shaping distinctly African-American art forms and expressions during a period when European standards dominated.