Google Earth Samples
I'm experimenting with ways to display WikiMarion content in Google Earth. Here are a couple of the things I've done. The individual .kmz files are linked below—they should open in GE if you have it installed—or here's a file with all of the layers together .
I made a couple collections of placemarks with historic photos  placed in their geographic locations. Here are some schools  and other historic buildings . I took some current photos of the same locations before leaving town, but haven't placed them yet in GE.
A past student, Ben Ogle, wrote a paper on the trolleys that ran through town from 1889 to 1947, which I've wikified here. He created some maps of the trolley routes using a paper map and highlighter, and I recreated the 1890, 1892, and 1901 routes  using GE's path drawing tools. You can click each of them on and off separately and watch the growth. There are a couple of photos, too, and lots more that could be added.
I found an image of the original town plan from the 1830s  and overlayed it on the current map. I tried to do the same with a scanned trolley map, but the stretching tools weren't fine-grained enough to get the map's streets in line with their actual locations. It would be nice if you could stretch different parts of an image in different ways, because the distortion isn't always uniform.
I spent a little time reading about sundown towns—places with signs, ordinances, etc. warning African-Americans "Don't let the sun go down on you in [city]" from the 1890s to the 1930s and beyond. It's a fascinating topic, which you can read about on James Loewen's webpage . (Marion wasn't such a town, though we had plenty problems of our own—more on that later.) I shelled out $20 for an upgrade to GE Pro, copied this list  of Indiana sundown towns into a spreadsheet and imported them onto the map . I haven't figured out how to make a map key yet, but red cities are definite sundown towns, orange are probable, and yellow are possible. There seems to be some dispute about Loewen's methodology in identifying towns, and I'm in no position to judge, so don't take this as an endorsement—just an interesting visualization.