Over 60 years after Adolf Hitler ordered its construction, the West Wall fortification system (or "Siegfried Line" as it was known in Britain) still survives. Overcoming the West Wall and the numerous river and forest obstacles integral to it was the culminating campaign of World War II in Europe. Six months of fighting along a 350-mile front left 250,000 American, British, Canadian and French casualties.Best-selling World War II historian Charles...