The Caulker Riots of 1858 and 1859 were a series of violent labor disputes in Fells Point and Federal Hill shipyards. Black caulkers trained under a master for five years, which is why they held a monopoly on caulking jobs. The Caulker Riots sought to end the monopoly, which ultimately led to the establishment of the Black-owned Chesapeake Marine Railway and Dry Dock Company in Fells Point in 1866.