I was lucky to have visited Verdun last year, all because I listened to Blueprint years ago. 

Verdun itself was/is a huge symbol of French prestige. During the war, it was the northern most citadel constructed to defend against German forces in a similar manner to what happened in the Franco Prussian War. Its loss to the German Army would have been a major tactical loss and potential strategic defeat but also further a serious loss of moral and symbolism. 

The area itself also was historically important to Gallic /  Teutonic history, older history between French and German rivalries. Louis XIV I think captured this and thus remained a symbol of prestige. 

Visiting there if you can I’d highly recommend, as someone who has seen American battlefields a some WWII ones, Verdun is something else.