United States. Department of Justice
National Archives and Records Administration
8601 Adelphi Road
College Park, MD 20740-6001
301-713-6800 (1-866-272-6272 )
4,000 maps and charts
Maps, tables, charts, blueprints, and photostats filed separately. Most were prepared as exhibits in particular cases. There are charts relating to patents of electronic equipment and radio broadcasting, 1930-1946 (file 60-11-24).