Historic aerial maps of Delaware, beginning in the 1930s and running to the present, are available online through a service provided by the Delaware Geological Service’s Delaware DataMil (Data Mapping and Integration Laboratory).
This virtual service allows researchers to easily acquire detailed visual representations showing the nature of development on parcels at specific points in time.. As an example, the plate showing the John F. Kennedy Highway where it crosses the Mason Dixon Line and the Elkton interchange has aerial views captured in 1937, 1954, 1961, 1968, 1992, 1997 2002, 2007, and 2010. Simply by clicking the mouse, the researcher has access to these valuable aids. Below are the 1954 and 1968 maps illustrating how the land appeared at those two points in time, a decade before the John F. Kennedy Highway was built and the other five years after its opening.
To provide another modern representation (2009), we used Google Earth to illustrate with fine detail how the tract looks now. By-the-way, Google Earth is another excellent research tool for finding old homes, cemeteries, streams and much more
Here is the link to the homepage with instructions.