Eric Jaffe: Why Historical Maps Still Matter

With 150,000 or so old print maps to his name, David Rumsey has earned his reputed place among the world's "finest private collectors." But the 69-year-old San Francisco collector doesn't have any intention of resting on his cartographic laurels. He continues to expand his personal trove as well as the digitized sub-collection he makes open to the public online — some 38,000 strong, and growing.

"I'm pretty old for a geek map guy," he says. "But I stay young by embracing new technologies all the time."

Rumsey, a native New Yorker, began his career teaching and practicing art — specifically, its intersections with technology — before getting involved in a charity on the West Coast. After starting his map collection Rumsey used that early art-tech interest to stay ahead of the digitization push. He's created a series of interactive maps that layer old prints onto the Google Earth and Google Maps platforms, and this summer he plans to launch a geo-referencing tool (similar to one recently introduced by the British Library) that lets users get involved in the digital mapping process themselves....