We show that Southern trade and the Southern economy were primarily harmed by the Confederate government’s economic and military policies. The Union blockade fleet and coastal bases were a necessary condition, but it was the policies of the Confederate government that made the closure of international trade and the destruction of the Southern economy possible. These misguided policies, more than any other factor, explain the unusual and unexpected effectiveness of the blockade in reducing trade and, ultimately in the defeat of the Confederacy, a result we label the “Confederate blockade of the South.”