I've become a huge fan of Sam Mustafa after purchasing LaSalle and Grande Armee, and so I've purchased Might & Reason too in impulse.
I recently became interested in the American Civil War, and started reading Might & Reason with the intention of using it to refight ACW. This was when I realized a mistake on my part: I had always assumed that Might & Reason were "grand-tactical rules for 19th century warfare", intended to be used for conflicts like the ACW or Crimean War.
Now I realized that M&R is actually for written for 18th (not 19th) century warfare, and more intended to be used for the FPW and such.
But then I was thinking... is 18C warfare all that different from 19C? If not, then couldn't I use Might & Reason to wargame the ACW?
Now I do know that this may be a hopelessly naive question, but I'm asking because I don't have the faintest clue about conflicts in the 18th century.