Mallows Bay is most renowned for its “Ghost Fleet,” the partially submerged remains of more than 100 wooden steamships that were built in response to threats from World War I-era German U-boats that were sinking ships in the Atlantic. Although the ships never saw action during the war, their construction at more than 40 shipyards in 17 states reflected the massive national wartime effort that drove the expansion and economic development of communities and related maritime service industries. The fleet was brought to the Potomac River to be salvaged for scrap metal by a company in Alexandria, Virginia, not far from the sanctuary site.