In Easton, Md., an untold story of free African-Americans is being discovered through bits of glass, shards of pottery and oyster shells. Piece by piece, archaeologists and historians from two universities and the community are uncovering the history of The Hill, which they believe is the earliest settlement of free African-Americans in the United States, dating to 1790. Treme, in New Orleans, is recognized as the oldest free black community in the nation, dating to 1812. But researchers say that could change based on findings from the Easton dig. "It's not just a black story. It's an American story," said...