Where is Cush?

Woe to the land of whirring wings
    along the rivers of Cush…
which sends envoys by sea
    in papyrus boats over the water.
Go, swift messengers,
to a people tall and smooth-skinned,
    to a people feared far and wide,
an aggressive nation of strange speech,
    whose land is divided by rivers.
Isaiah 18:1-2
            Cush is modern day Ethiopia in Africa.  Moses married a Cushite woman.  Jeremiah 13:32 asked if a Cushite could change the color of his skin?  Obviously they were black, tall and spoke a different language.