ALEX CHADWICK, host:
This is DAY TO DAY from NPR News. I'm Alex Chadwick.
MADELEINE BRAND, host:
And I'm Madeleine Brand.
In a few minutes, a new book looks at the media's role in the civil rights movement.
CHADWICK: First, back in 1896, the civil rights pioneer W.E.B. DuBois drew a map of one section of central Philadelphia. He highlighted each house where African-Americans lived, and he color-coded them to indicate whether the people who lived in them were middle class or poor or - in his term - viscous and criminal.
BRAND: That label stops you cold. So do the swatches of color on the map of the city. As Dan Charles reports, maps have since gone high tech, but the best of them still don't just describe our world. They get people to change it.
DAN CHARLES: Hanging on the wall of Amy Hillier's office at the University of Pennsylvania School of Design, there's an oversize copy of the map that W.E.B. DuBois made. For Hillier, it's an inspiration.
Professor AMY HILLIER (University of Pennsylvania School of Design): He always believed that collecting information was about social change, and that he had an obligation to advocate for the change - not just to publish the research and go onto the next study.
CHARLES: Hillier also draws maps of urban landscapes, but hers are built from mounds of data - statistics on wealth in particular neighborhoods, traffic patterns, crime - basically anything that has a location. And those maps are turning out to be very useful for community activists like Duane Perry.
Mr. DUANE PERRY (Founder, The Food Trust): We're on the commercial strip to this neighborhood - Woodland Avenue.
CHARLES: It's an old section of southwest Philadelphia - a little down on its luck, but there are plenty of shops here open for business.
Mr. PERRY: There're banks, there're exterminators, there're (unintelligible) shops.
CHARLES: Perry has lived in Philadelphia his whole life. He founded The Food Trust, an organization devoted to helping people get affordable, nutritious food.
Mr. PERRY: You name it, there's a place here that you can find it.
CHARLES: For years, though, you couldn't find a good grocery store. They'd all gone off to neighborhoods with space for big parking lots. So Duane Perry and The Food Trust started campaigning for a city program that would bring grocery stores back.
Mr. PERRY: We went around town talking to folks and saying Philadelphia needs 70 more supermarkets. And we didn't get quite laughed out of offices, but people would look at us and their eyes would glaze over, and they'd say well, you know, that's nice. But boy, that's a lot. You know, we don't think that there's that much of a need.
And so we realized that we had to present the information in a way that was a little bit more compelling. And so we began to think about ways to map this information.
Charles: Map it.
Mr. PERRY: Map it.
CHARLES: Perry went looking for a mapmaker, and he found Amy Hillier.
Prof. HILLIER: We sounded like we were a good match for each other, and I was cheap.
CHARLES: Hillier was, at the time, a graduate student at the University of Pennsylvania, becoming an expert in the field of Geographic Information Systems - or GIS. It's a booming field. Businesses, governments, and scientists are riding a flood of location technology from GPS receivers to the aerial images available through Google Earth or Microsoft's Local Live. Hillier says many people are using the technology to make a buck.
Prof. HILLIER: Where should that next Starbucks be? Where's the most cost-effective place to build a condominium or a new housing development? For me, it's really about attacking disparity.
CHARLES: Disparity, for instance, in the distribution of supermarkets. She set to work gathering three kinds of information: first, supermarket sales in Philadelphia, store by store. Also, average income in each one of the city's 1,800 census blocks. And finally, how many people in each census block had died from diseases linked to poor diets, such as heart disease or ailments associated with type 2 diabetes. Then she combined them all on one map.
Prof. HILLIER: That's the brilliance of GIS. You can take data that were collected - maybe you pulled some data down from the census, maybe you have a satellite image. In theory, you could put these all together. Now, the trick is getting everything to line up. But basically, it works.
CHARLES: She ended up with a splotch of red across the face of Philadelphia - a broad swath of low-income neighborhoods that lacked places to buy good food. In many of them, people were dying in greater numbers from diet-related diseases. Duane Perry from The Food Trust says when he put that map in front of local leaders, the information hit home in a way he'd never seen before, and things began to move.
Dwight Evans, who chairs the Appropriations Committee of the Pennsylvania State Legislature, pushed through a new, $30 million fund that provides subsidies for supermarkets in neighborhoods that most need them. Evans is now running for mayor of Philadelphia.
Mr. DWIGHT EVANS (Chairs Appropriations Committee, Pennsylvania State Legislature): I already knew it was a problem. The map just made it real. The map just put a face on it. It was like an exhibit in a court. That's what it was. That's what it did.
CHARLES: And on Woodland Avenue in southwest Philadelphia, there's a supermarket again, one of 21 new stores that have opened with the aid of state funds. Amy Hillier, the GIS expert, has moved onto other projects. Among other things, she's recreating - with modern technology - that map that W.E.B. DuBois made of Philadelphia's 7th ward - just a mile from Hillier's office - a century ago.
For NPR News, I'm Dan Charles.