Update of Maps Online

The David Rumsey Map Collection, which is integrated into Google Earth as a Gallery Layer, just added 2,174 old maps. When I say that the maps are integrated into Google Earth, what that means is that you can overlay a historical map over a modern one and see where the old features match the newer maps. This is very useful for finding places that no longer appear on modern maps such as changes in street names. The additions to the David Rumsey Map Collection brings the total of old historical maps on that site alone to over 34,000 maps.

But of course, this huge site is only the beginning. If you want to see more of what is available, then you should take a look at Old Maps Online. This site allows the user to search for online digital historical maps across numerous different collections via a geographical search. Search by typing a place-name or by clicking in the map window, and narrow by date. The search results provide a direct link to the map image on the website of the host institution.

OldMapsOnline has been created by a collaboration between The Great Britain Historical GIS Project based at The University of Portsmouth, UK and Klokan Technologies GmbH, Switzerland.

The Australian site, Trove.nla.gov.au has links to 380,971 historical and current maps online. Here is an example:

And don't miss the online collections of maps at the Library of Congress's American Memory project. Although their collection is not as large as some, they may have the map you need. Here is an example:

Of course, you know about the United States Geographic Survey's efforts to digitize all of the topographical maps every drawn in the United States? If not check out the Historical Topographical Maps and while you are at it, look at the U.S. Board on Geographic Names. 

How about an example of a topo map from the USGS:

This is just a start. You could spend several days online just looking at historical maps and never get past some of these sites to the hundreds of others. I am always totally flabbergasted when someone tells me that they have searched everywhere for an ancestor, when I know that this is not physically possible in one lifetime. 

Oh, and did I mention Google Maps and Google Earth? And did I forget to mention the 500,000 items in the Harvard Map Collection? Did I miss the Ordnance Survey in the UK? Oh, and what about Europeana? One last example from Europeana:

And did I mention...