Why was the Fifteenth Amendment unable to protect African Americans' voting rights?

Read these lines from "o captain! my captain! ". o the bleeding drops of red, where on the deck my captain lies, fallen cold and dead. how does whitman use the extended metaphor to refer to lincoln’s death? a. whitman compares lincoln’s death to what the death for all the soldiers was like. b. whitman compares lincoln’s death to the loss of one of the army generals. c. whitman compares lincoln’s death to the loss of losing a family member in the war. d. whitman compares lincoln’s tragic death to a captain lying dead on the deck of his ship.