"Down in the Bottomlands" is a novella written by Harry Turtledove, set in an alternate reality in which the Messinian salinity crisis continues to the present day. It won the Hugo Award for Best Novella in 1994.
From the master of alternate history comes an epic of the Second Civil War. It was an epoch of glory and success, of disaster and despair. Twenty years after the South won the Civil War, America writhed once more in the bloody throes of battle.