I seek an electronic copy of a map that shows the outline of
Prussia--preferably shortly before it's extinguishment during WW
I--overlayed over a current map of the region.

Dear mostcuriou,

Here is a map that shows the outline of Prussia in 1914 (in red) over
a current political map of Central Europe (image size: 524 x 403
pixels, 386 kB) :

http://home.foni.net/~scrippor/prussia.jpg


I made that map myself by using these sources:

University of Texas Library Online: Europe Maps - Central Europe
www.lib.utexas.edu/maps/europe/ central_europe_pol01.jpg

FamilySearch: Research Guidance - Map of the territorial growth of the
Kingdom of Prussia
www.familysearch.org/eng/Search/ rg/images/page_3.gif

Atlas zur Universalgeschichte (History Atlas), published by List
(Germany), 1980. ISBN 3-471-40430-9

Please note that the red lines inside the main body of the Prussian
territory are correct; those are minor German principalities and the
Free City of Hamburg, which were completely surrounded by Prussia.

Hope this is what you were looking for!
Best regards,
Scriptor

Thanks--nice job.

I tried editing maps from www.euratlas.com to create such a map, but
failed.

Take a look at "What 19th Century Provinces Belong to Poland?" at
http://www.polishroots.org/genpoland/changes.htm. It shows the
provinces of pre-WWI and Weimar Prussia against the map of modern-day
Poland.

Another page at the Polish Roots site,
http://www.polishroots.org/genpoland/eastpr.htm, shows the post-WWII
division of East Prussia between Russia and Poland as well as the
Lithuanian annexation of Klaipeda, the former Memel Territory.

"Historical Geography of Poland" at
http://freepages.genealogy.rootsweb.com/~atpc/heritage/history/historic-geography.html
has small maps that superimpose the shape of modern-day Poland over
pre-WWI maps of the region.

For a map of pre-WWI Prussian provinces, see
http://www.deutsche-schutzgebiete.de/webpages/Koenigreich_Preussen.gif.