This resource is made up of three separate Google Earth map files in the .kmz file format. Two of the three are located in the Map Files box to the left of this box, however, the third file is too large to be hosted on this system. All three of the files can be downloaded here.
Upon opening the files, there will be two control panels at the left hand side of the screen. The top panel controls which layers are visible on the map.
Each period has a separate map overlay both because street names and numbering have changed over the years as well as to give a sense of historical context. Many pins also include map details with existing structures labeled with varying degrees of granularity to communicate a picture of what the city was like at specific points in its history. Some pins also include links to related online resources.
Each period uses text of a different color to label each pin or polygon indicating a site of interest. Pins and polygons are color coded.