Anyone wishing to take an online map into the field should consider printing a copy. Commercial providers, such as FexEx Office, offer large format printing services in person and online. University of Delaware users may consider two on campus locations for printing large format materials.
Links to pages which offer scanned printed maps of Delaware. Current and archived PDF Delaware topographic maps (from DataMIL) are linked from the State Maps & Data guide.
From: D.G. Beers, Atlas of the State of Delaware, 1868. University of Delaware Library Digital Collection.
Sanborn Fire Insurance Map from Newark, New Castle County, Delaware. Sep 1891. Sheet 2. (Library of Congress) (https://hdl.loc.gov/loc.gmd/g3834nm.g012211891) List of Delaware maps
A collection of maps which depict the commercial, industrial, and residential sections of some twelve thousand cities and towns in the United States, Canada, and Mexico and date from 1867 to the mid 1960s. The maps were used to gauge the fire risks for urban structures and display detailed information about buildings, including the outline of each building, the size, shape and construction materials, the function of structures, street names, and house and block numbers. The maps were hand-drawn and colored. These were published by the Sanborn Map Company, the primary American publisher of fire insurance maps.
A listing of printed materials available for use in the Library.
The United States Congressional Serial Set Map Index contains a wide variety of maps on topics as predictable as Armed Forces and Conflicts or Discovery and Exploration to those as unexpected as the Almshouses and Asylums. You can find for example the map titled "Boston in 1880, showing societies (secret and benefit), hospitals, asylums and homes." Maps included date to before 1799. For example if you were studying the Roman Empire you might find interesting a map of the "Main road system of the Roman Empire as shown by the Itinerary of Antonine (A.D. 150) and the Itinerary to Jerusalem (A.D. 333). From Parthey and Pinder."
U.S. Congressional Serial Set Map Index help screens provide assistance in searching for maps.