USA Today has continued its coverage of environmental contamination with a new series on Ghost Factories. Investigators used Sanborn Maps and City Directories to pin-point the location of hundreds of historical lead smelters that once dotted the nation and left behind a legacy of residual contamination in soil and groundwater.
As part of the series, USA Today visited the Library of Congress and got the behind the scenes tour of their impressive Sanborn collection. Check it out!
And stay tuned; coming up next week, we have great video footage about why only some Sanborn maps are available in color and why the company switched exclusively to black and white maps years ago.