This is a highly interesting map, as it shows what never was. Created soon after the end of the War of 1812, the map details the possible placement of forts to protect the mouth of the Patuxent River. It was the British Navy's relatively uncontested travel up the Patuxent that allowed them to march troops from Benedict to burn Washington in August of 1814. Major J.J. Abert, who fought in the battle of Bladensburg, probably would have been personally interested in the creation of this map. Eventually Abert went on to command the Corps of Topographical Engineers for over 30 years leading up to the Civil War. Read more about Abert here.
Download Map (475 MB .tif)