Before government engineers can deepen one of the nation's busiest seaports to accommodate future trade, they first need to remove a $14 million obstacle from the past -- a Confederate warship rotting on the Savannah River bottom for nearly 150 years. Confederate troops scuttled the ironclad CSS Georgia to prevent its capture by Gen. William T. Sherman when his Union troops took Savannah in December 1864. It's been on the river bottom ever since. Now, the Civil War shipwreck sits in the way of a government agency's $653 million plan to deepen the waterway that links the nation's fourth-busiest container...