Fort McHenry and Baltimore's Harbor Defenses - Hardcoverby Merle T. Cole (Author), Scott Sheads (Author) Few residents or visitors to the Baltimore metropolitan area understand the strange concrete structures they routinely pass when crossing the Francis Scott Key Bridge or glimpse while fishing or boating in the Patapsco River, but the treasured heritage associated with these noble structures is a part of our collective past. Fort McHenry and Baltimore's later harbor defenses played significant roles in