The dollar has benefited mightily from the abandonment of commodity money, the Bretton Woods system, and the rise of competing fiat currencies. This is partly why the dollar has come to dominate international trade.
MacMillan's book provides many insights into the true vileness of war, although she strays into some dangerous areas when she accepts the faulty economic notion that wars bring economic benefits through government spending.
The fact that some Americans supported slavery in the eighteenth century is not at all remarkable. Most of the world agreed with them. What is remarkable is that many of them sought to abolish slavery in the new republic.