D bar chocolate ration
Probably the hardest to find of the WWII US rations!
Created by Hershey Chocolates to provide a portable, compact, high energy supplement to the diet of the G.I. in WWII and could be used for hot chocolate or added to coffee.  Few examples have survived WWII!
This bar is intact and unopened and the only one I've encountered for sale! Note that it was manufactured by Cracker Jack Co., not Hershey.
$185.00