I think the South did have a chance to win even if it was a small chance. They knew in the beginning that the odds were against them and they found ways to circumvent this. They knew that they could not win a war head on with the North. A war of attrition had to be fought for the South to have a chance. Who ever could hit the hardest, and most importantly survive the longest could win by wearing down their opponent. The South used this to try to hit Northern morale. They would make the North sick of war to ensure their existence. The South also had the advantage of cotton.

The South could have used cotton to get some European powers into the conflict. Like the Colonists in the Revolution, foreign support would have helped the rebels considerably. Their allies would be able to bring in supplies and soldiers as well. These countries can also recognize the South which could force the Union to recognize it as a separate country.