The actual house, on Fifth Street north of Arch, was demolished in the 19th century. Dexter's name, once prominent in the city's small but vibrant free black community, vanished as well. But an archaeological dig four years ago brought Dexter's home site and identity back from historical oblivion.
Now Drexel University students have built a digital model of the house, seeking to reconstruct it with historical accuracy as part of an ambitious long-range effort to rebuild colonial Philadelphia and its environs - in three-dimensional interactive virtual reality.
Even though the project is very much in its infancy, there is nothing quite like it elsewhere in the country, although the University of Virginia has created an extensive virtual ancient Rome (http://www.romereborn.virginia.edu/) and MIT has started and stopped a few projects.
Drexel's project is part Second Life virtual world, part social and economic history, part video game, part computer science, part teaching tool.
"What we hope to do is create a 3-D interactive environment for teaching and learning about colonial American history," said Glen Muschio, digital media program director at Drexel.
"As AI [artificial intelligence] capabilities develop, we hope that the interaction will get to the state where we can really do this on a big scale and people can get involved in role playing. That's where we're headed. Right now, were building the spaces in a photo-realistic way."
"Colonial Philadelphia: The Game," joked Chester Cunanan, a 23-year-old graduate student who has worked on researching and building the Dexter house and other parts of the project.
Jokes aside, what Muschio envisions is the rebuilding of the 18th-century city and its economic ecosystem, ultimately peopling buildings with avatars - digitized characters - who will show visitors around, explaining the objects found there, bringing them to viewers for inspection, and describing the significance of the site.
In some cases, visitors might even be able to move through ongoing battles that took place around the city during the Revolutionary War. But the technology is not quite there yet.
All is created with as much historical and physical accuracy as possible. Actual artifacts taken from the ground at the Dexter site, for instance, will be scanned and reassembled in virtual space. Satellite imagery has already been utilized to create the landscape surrounding Fort Mercer, a largely vanished earthen bastion across the Delaware River from Philadelphia that helped defend the city against British sea power.
The fort itself is being re-created from historical records. Whitall House, home of the wealthy Quakers whose plantation served as the site of the fort, still stands, and 3-D Colonial Philadelphia - as Muschio has dubbed the project - has made use of Whitall's physical reality to create a virtual double.
With Whitall House, it is possible for visitors to actually enter rooms and move about in the virtual spaces, although they are relatively empty. (The Dexter house is still "closed" to visitors at the moment because not much is currently known about what the interior spaces might have looked like.)
The Augusta, a 64-gun British war ship that ran aground near Fort Mercer and was blown up, is also under construction.
"We are working with the computer science department here at Drexel, which is interested in creating algorithms that will allow them to work with the [National] Park Service to virtually reconstruct the [Dexter] artifacts, based on the remnants that were uncovered," said Muschio. "We're also working with information-science technology to create databases so we can get a handle on all of this stuff, because we hope to make this available to other researchers in other cities who might not have the types of resources we have in terms of window types, brick face, things like that."
What that means is creating a database of 18th-century Philadelphia doors, windows, brick faces and other common features that can be dropped into a scene or a row of houses quickly. Whole blocks, which might have sketchy historical records at best, could then be built up with some measure of authenticity.
Brian Gadomski, a 19-year-old freshman, has already spent a great deal of time building an archive of 18th-century house doors and windows. He works from blueprints from the Historical American Building Survey.
"I'm bringing them into 3-D and I'm tracing them in the computer, and building, based on the original drawing, a geometry that matches exactly with those. It's a process that's relatively simple but will allow us to create a data base of doors and windows that can be used eventually in the complete Colonial Philadelphia."
The project is still small, fueled by the interest and enthusiasm of students and faculty, and minuscule amounts of money. The group has received a small grant from the university to explore use of the 3-D recreations in the teaching of fourth-grade American history. (The group has also re-created Franklin Court and the mill drivetrain at the Anselma Mill in Chester County.)
But hooking fourth graders into an interest in American history is only one small possibility inherent in the project. The simulations, for instance, could also provide historic sites with virtual support for real visitors at the real places.
"What we hope to do is, through the use of videotapes, 3-D models, create a Web site with downloadable podcasts so that people can load up their iPods and bring them to the site and do self-guided tours," said Muschio. Visitors to this as-yet-to-be-created Web site, will be able to view videos of Whitall House and its docents, for example, before visiting the actual house; downloaded clips can be used on visits when docents might not be available.
Students, for the most part involved because of their interest in technology, are hooked.
"I actually learned a lot about the Dexter house while doing it," said Cunanan, the graduate student. "How they had the first meetings there that eventually led to the first African American church in Philadelphia and how the Quakers worked with that.
"When you first start, it starts as a 'project,' but then you have to learn about the history of the place to build the place properly, and then the history catches you at that point.
"So when it starts, yes, we're not totally interested in history, but when it ends, you're not only interested in the place, but the history and the place. The history pushes you forward, the impetus that drives you after the initial 'Oh, yeah, a new thing to play with!' wears off."
Contact culture writer Stephan Salisbury at 215-854-5594 or firstname.lastname@example.org.