In paragraphs 5-6, FDR begins most of his sentences with the words “I saw;” Why is this structure effective in helping FDR convey his message?

Which pair of uses of figurative language from “the caged bird” support the extended metaphor of freedom versus oppression? back of the wind; floats downstream his wings are clipped; his feet are tied the caged bird sings; the free bird thinks dawn bright lawn; grave of dreams