The map on this page is a combination of data on early US colleges until 1866, railroads in 1870, and population density in 1900. Pins represent each college, lines represent railroads, and green/red colored regions represent the relative population density of that area. The combination of these three data sets yields interesting results. Almost all colleges established by the mid 19th century are placed on a railroad line and/or are situated near a region with high population density.
I’m quite impressed with ArcGIS’s mapping software. There are a lot of useful features that allow you to visualize and share relationships between datasets.