Checkers' Mate!

This Sunday-sized puzzle, which first appeared in the holiday (December 2014/January 2015) issue of Natural Selections, as accessed here, was created in the 40th anniversary year of a major chapter in American history (pictorial hint to the right). After completing the puzzle (spoiler), learn more about THIS WILL BE ADDED OVER THE NEXT FEW DAYS.

Click here (two pages) or here (one page, for those with good eyesight) to view or download the puzzle in PDF format; here to download it as a puz file; here to download it as an ipuz file [requires the free Puzzazz app to solve]; here to solve the puzzle interactively (thanks to Jim Horne); here for the solution. We thank Ralph Bunker, John Child, Laszlo Denes, Charles Flaster, Katherine Halpern, Brent Hartzell, Martin Herbach, Arlene Romoff, Ellen Ross, Markand Thakar, and Alex Vratsanos for beta testing the puzzle and many helpful suggestions that improved it.

If you want to tell others about this particular page, refer them to
http://tinyurl.com/checkerspuz

More puzzles here (all), here (political), and here (tributes).

E-mail barany@umn.edu to be added to a bcc distribution list.