Historic Map Works was formed to create a historic digital map database of North America and the world, and it claims to draw on the largest physical collection of American property atlases.
Adding to its own own atlas collections, the Maine company has also incorporated scans of antique map collections from the Osher Map Library and Smith Center for Cartographic Education (University of Southern Maine). Combining the collections provides data covering several centuries.
Included maps come from US property atlases, antiquarian, nautical, birds-eye views, special collections (celestial, portraits and more), directories and other text documents. Currently, there are more than 1,181,308 individual images. For more information on the maps, click here.
You can also find 4,623 antiquarian international maps from 1,433 atlases. click here for a list of maps by country.
There are two ways to access Historic Map Works. Individual subscribers can view it here, while the Library Edition is distributed by ProQuest to public libraries and universities.
If you are a member (registration is free), view images in limited formats, but you must have credits deposited to your account to download a PDF, JPG, rotate, crop or print images. Enhanced access is via credits (credit card/PayPal) for pay-by-visit or via subscription ($29.99 per month for limited premium features; $249.99 for an annual subscription for full premium features, including built in credits for specific functions).
I found it to be a rather confusing system, although the annual subscription seems to offer the best deal. it is still rather expensive if you are looking for maps, for example, covering only one country. If your public library has the ProQuest Library Edition, that's a much better way to access these resources.
According to the site, members can track ancestors to their homes; see the roads they traveled, and the names of their neighbors. Multiple layers allow members to see an area change over time, and the site's Geocode feature allows comparison of historical and modern maps.
Maps are scanned at high-resolution, uploaded and cataloged for viewing, and geocoded to allow address searches on a modern map. Linking historic images with such data allows researchers to search by modern day address or coordinates. Viewers can also browse by geographic location, keywords, town names, mapmakers or by year.
The company also offers archival prints of the maps and giftware, so think gifts.