http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Historical U.S. county outline map collection, 1840-1980
1 atlas (1 portfolio (15 folded leaves)) : maps ; 60 cm.
senior editor Thomas D. Rabenhorst, general editor Carville V. Earle ; cartographers Jeff Anzevino, Barbara Plunkett.
"U.S. county boundary maps for the census decades"--P. 2 of portfolio cover.
Scale of blank national county maps approximately 1:12,000,000.