Complex sentence: Elizabeth (Bessy) Marbury's clients ranged from the French Academy of Letters, to playwrights Oscar Wilde and George Bernard Shaw, to the dance team of Vernon and Irene Castle, as well as being an early promoter of African American writers of the Harlem Renaissance.
Split into simpler sentences: Elizabeth (Bessy) Marbury's clients ranged from the French Academy of Letters to playwrights Oscar Wilde and George Bernard Shaw; to the dance team of Vernon and Irene Castle. She was an early promoter of African American writers of the Harlem Renaissance.