Amateur archaeologist Tom Garner had time to kill and took a drive along Pensacola Bay in the Florida Panhandle. Spying a newly cleared lot, he poked about, hoping to find artifacts from the city's rich history dating back centuries to the Spanish explorers. Garner stumbled upon some shards of 16th Spanish pottery. "There it was, artifacts from the 16th century lying on the ground," said Garner, a history buff whose discovery has made him a celebrity in archaeological circles. Experts have confirmed the find as the site of the long-lost land settlement of a doomed 1559 Spanish expedition to the...