<p>TAMPA -- Explorers believe they have found the sunken remains of an 1860s steamer that could yield the richest cargo ever recovered from a shipwreck: thousands of gold coins worth as much as $180 million.</p>
<p>The SS Republic was carrying 59 passengers and 20,000 $20 gold coins from New York to New Orleans when it sank in a hurricane off Savannah, Ga., on Oct. 25, 1865, according to newspaper accounts and other historical records.</p>