Let's collect some good example maps for use in K12 education. Reply to this thread with examples you see that educators can easily use.
Regardless of one's politics, it is important for students (and educators) to see that maps help make a point. The White House has been using ArcGIS Online maps in more and more activities. You can see one at the bottom of the page describing the Iran deal:
For social studies educators, this can be a good example of why to get comfy with GIS, even if only basic tools. This map does two very simple but powerful things: Show at a glance the international support (if only in a binary way), and give short paragraph popups with a link for each country in favor.
I always contend "It is far more impressive seeing people do powerful things with simple tools than simple things with powerful tools."
Here is the link to the movie created by the teachers at Kemps Landing ODC that presented at ISTE this past summer. Am working with them again this year to take things to the next level, wherever that may be.
Maps highlight patterns of social inequity or injustice. See this example from Baltimore, and a related Huffington Post article. Getting students to understand they can make a big difference with a good map is important. One can launch change thru maps as well as thru articles, speeches, or marches.