"If I could save the Union without freeing any slave I would do it, and if I could save it by freeing all the slaves I would do it; and if I could save it by freeing some and leaving others alone I would also do that."
- Abraham Lincoln to Horace Greeley
Washington, August 22, 1862.
 
So the war was not primarily about slavery. Lincoln was interested in preserving the union so that he would continue to have the financial resources of the South to run the government.
 
Blackwater also tells the story of John Geoghegan and how he became a successful blockade runner out of Pensacola Bay. It's the story of Maria Moreno, the Spanish beauty whom John loves and almost loses. Further, it is the story of John's friend, Ben Jernigan, who is engaged to French-educated Amanda Rucker. Ben has no interest in the war, so he hides in the Yellow River swamp to avoid conscription. But he finds himself drawn out to help his friend, Caleb, a slave who has killed in self-defense. He gets Amanda and her friends out of Milton, Florida, and finally leaves the Southern ruins with John and his friends on his ship, the Carolina.