Old maps are useful sources for just about anyone interested in history. Maps easily convey change over time, as they show the expansion of cities, regions, or countries. They also provide useful context to help understand where historical events took place. Thankfully, historical maps are increasingly accessible online for those of you unable to spend days in the map library at the British Library or another comparable repository.
A growing number of professional historians are using Geographic Information Software (GIS) to study historical maps and their relationships with other geographic data from the past. David Rumsey’s map collection and Google Earth allow non-experts much of the same functionality of the complex and expensive GIS software and make it possible for all historians to examine maps that have been “pinned” on the the satellite imagery in Google Earth. This allows direct comparisons between the old maps and the modern landscapes.
The David Rumsey’s historical map collection provides an amazing collection of historical maps and globes. A large number of these maps are Geo-referenced or “pinned” onto the digital globe provided by Google Earth. Rumsey Historical Maps are included in Gallery of Google Earth. Open the Gallery (found in the the menu on the bottom left hand side of Google Earth) and click on Rumsey Historical Maps to add them as a layer on the digital globe. Once you have done this a few hundred compasses will appear in Google Earth (zoom in and out and navigate around the world to see them all). Find a map that interests you, such as Pownall’s 1786 map of North America and double click on the compass. A box will appear with the map. Double click on the map and it will appear as a layer in Google Earth over top of the satellite image of North America. Once the map has been overlayed you can navigate around and zoom in and out in the same way you do with the normal Google Earth maps. The collection of maps is extensive and growing. The focus of the collection is the USA, but there are still lots of maps of other countries and cities around the world. The Canadian content includes a number of North American maps, two maps of Montreal, two maps of Quebec City and one of Lower Canada in 1815.
Another great online resource is the University of Toronto map library website. At this point in time they have 105 digital maps and aerial photographs posted on their website (many of which are in high resolution). They range from local neighbourhood maps of Toronto to a map of Australia. The map librarian, Marcel Fortin, also worked on a NiCHE sponsored project with Toronto historian Jennifer Bonnell to create a GIS database of the Don Valley. The website if full of information about their findings and they have posted the data online in a variety of formats, including the Google Earth KMZ. This allows any user with the free software installed on their computer to download layers showing the growth of industry and the loss of streams and creeks (among other things) from the mid-nineteenth century to the mid-twentieth century.
Finally, the Mannahatta Project is one of the most interesting historical mapping projects on the internet. The video below provides a step by step explanation about all the methods used to digitally recreate the landscape of Manhattan Island at the point of contact between Native Americans and Europeans in 1609. Like the historical maps on Google Earth, users can navigate through this dense urban landscape and compare it with the recreated past landscape.
Based on this incomplete sampling of historical map resources on the web, I think the rest of the historical field could learn a lot from the successes of David Rumsey, Marcel Fortin and Eric W. Sanderson to better presents historical information on the web. Please let us know about other free historical map collections or interesting projects on the internet in the comment section of this article.