I created a map of the British defenses of Philadelphia in 1777. I chose to show all the redoubts built by the British because they show the strong points in the British land defense. I also chose to show British coastal defenses along the Delaware meant to defend the city from waterborne raids to form a more complete picture of their defenses.
Creating this map gives me a tool to understand the British tactical situation in Philadelphia during the occupation. It shows that they expected a land attack from the North, or at least felt that was the most vulnerable part of the city. It also shows they primarily relied on the Schuylkill River for their western defense, and the Delaware for their southern and eastern defenses. All of this makes sense, as both rivers would make formidable barriers to attack if defended properly, while the north would be vulnerable without entrenchments. The coastal defenses, consisting of a few cannon mounted in batteries, shows they expected nothing more than a harassing force from the river, incapable of serious threat, which is a fair assessment of the American navy at the time. Combined with other sources, this could be used as anything from a study of British tactics to a study of the role of terrain in warfare to even showing what parts of Philadelphia were considered important to defend.
One problem I had with creating this map was my source. I used a list of Philadelphia defenses provided by the American Forts Network. While their website does have a bibliography, I did not check their sources for myself. I would not be comfortable using this map in my work until I got to examine the original sources myself. I also had trouble with some of the street names for streets that have changed or no longer exist, so I used the David Rumsey map collection to cross-reference everything with an old map of Philadelphia overlayed on a current map to place my points. Also, four of the redoubts were listed as having an unknown location, which could affect my analysis if they were placed to the west or south, for example.
As a sidenote, one random feature of Google Maps that I like is the ability to import custom icons, which can be easily made in GIMP for example. This may be mostly a cosmetic feature, and not really affect my analysis, but they seem to fit my map so much better than the standard Google pinpoint.
You can view my map here
And here is the list of defenses I used