This is a ridiculously cool and unique usage of Google Maps’ API. Developer Brad Thompson aims to launch a platform where you can not only see what city blocks looked like in the past, but you can view what businesses inhabited the city long before you lived there. That platform is Pastmapper.

Putting old city listings and directories on top of the Google Maps API, Thompson gives an old world a new life, thanks to technology.

Here’s how Thompson explains Pastmapper:

For quick access to realtime information, (photographs, Tweets, business listings, weather, voting results, etc.), online maps are incredibly powerful tools. The more realtime the information is, the more valuable it is, and maps are in a constant state of being updated to keep up with the world. These tools are generally suited for answering a question that begins ‘What is happening?” or “What just happened?”. A few amazing examples of current data on maps are Eric Fischer’s racial distribution maps, the Oakland Crimespotting map by Stamen Design and the New York Times Hurricane Tracker.

But what if your real interest is what happened further back in the past? Online maps today simply add layers of information onto today’s map. Pastmapper is a first step towards answering ‘What was here?’ or ‘Whatever happened to..?’, by delivering a map, not just a data layer, that takes a fourth-dimensional view.

San Francisco in 1853

The first map released on Pastmapper is San Francisco in 1853. You can click around on the markers to get information about the businesses that were there during that time. Everything from bakeries to liquor stores are shown in an extremely condensed portion of San Francisco. If you click the button to see the map in 2011, you’ll see how many streets and detail have been added to the city since the 19th century.

Convofy 71 520x209 What did San Franciscos map look like in 1853? Check Pastmapper

The project is fascinating and hopefully Thompson continues to add more cities, as the power of publicly available information can help recreate experiences long before there was a Google Maps API to build on top of.

Pastmapper