The success of the city's seafood industry filled the city with train soot and large quantities of oyster shells. Around the turn of the 20th century, businessmen would buy plots of land at the southwest edge of the city and discard the shells and soot into the salt marshes. This shell midden eventually grew to become a peninsula roughly a half-mile long. Downtown Crisfield was built atop this new land, and this leads to the common statement that Crisfield was so prosperous that it is "literally built on top of oyster shells".