The Washington Map Society and its association with the Library of Congress Geography and Map Division (click HERE) will provide unique or interesting material to be listed here. We use links rather than embedded material so everyone can take advantage of the LOC viewers in high resolution. If you have a theme you think would be interesting, please hit the Contact Us link at lower left and send it to the WMS.
Ed Redmond (LOC and WMS) and Manuel Knight (WMS) provided the impetus and material for these timely links of thematic maps of political cartography:
Each election we [Library of Congress Geography and Map Division) prepare maps showing the official results of elections (once they are certified, etc.) such as this 2008 map of the Electoral College results: http://www.loc.gov/item/2008626928 . Our historical collections include similar thematic election maps such as this 1856 map: http://www.loc.gov/item/2012586610 .