The Most Expensive War in History\n\n In addition to the toll in human lives and suffering, countries spent more money on World War II than in all previous wars put together.

It was America's costliest war ever\n\n America's final bill for the fighting in the Pacific and Europe was massive. Adjusting for inflation, World War II cost overR$4.1 trillion, according to 2010 figures from the Congressional Research Service.