 Angelou returned to the same poem she based the title of Caged Bird upon for the title of A Song Flung Up to Heaven , from the third stanza of the Paul Laurence Dunbar poem " Sympathy " . Along with Shakespeare , Angelou has credited Dunbar with forming her " writing ambition " . The caged bird , a symbol for the chained slave , is an image Angelou uses throughout all her writings . 
