This post goes over another lesson from the Programming Historian, this one covering the uses of GoogleMaps and GoogleEarth.
The first part uses the My Maps feature of Google Maps. Creating a new map was very intuitive. After titling the map, I imported the sample data concerning various fat exports to Britain in the mid-1890s. I then had to tell Google which columns of the uploaded spreadsheet correspond to places and which to information to be linked to those places.
On the map produced, all places had the same default marker, and this was changed by going from uniform style to “Style by data column: Commodity.” This option gave each type of commodity its own color, with the ability to customize the colors and icons further.
Next, I added a new layer by clicking new layer and changed the base map to satellite by selecting that option at the bottom of the editing panel.
Then to practice putting place markers, in, I used the place marker tool to place some markers. Similarly, I used the tool next to this to draw some polygons around a couple of lakes and to highlight a road that runs between them. All of these markers, lines, and polygons were added to the new “Layer 2” as seen in the side panel.
The second part of the lesson uses Google Earth. After downloading and exploring how it works, the first steps of the lesson were to look at the Rumsey Historical maps by selecting them to appear in the layers pane. This brought up icons where there were historical maps ready to be overlaid. For an example, this 1815 map of Quebec City and the surroundings.
The next part involved importing a saved map, and for this I used the map that I had just been working on as the example St. Lawrence Seaway map wasn’t currently compatible. This was as simple as opening the saved KMZ file.
Next was drawing a polygon of Lake St. Clair, which worked much as in the Google Maps.
The most interesting part was to overlay a historical map onto the satellite images. For this I found an 1886 map of Duluth, MN. To input it, I selected the overlay button and browsed to find the right JPEG image. Then came adjusting of the map to align with the satellite imagery.