By many measures — obviously industrial and military, but also in education and logistics — the US Pacific Fleet in WWII could be the most impressive achievement in human history. Within little more than two years after Pearl Harbor, the US had built a fleet of +4000 ships, including ~70 aircraft carriers with a total compliment of ~ 2500 aircraft between them (numbers approximate because any endeavor of such a scale varies from day to day).

When you think of the industrial effort behind building all those ships and all those planes, then the effort behind training all those sailors, seamen and pilots, THEN the sheer logistics behind keeping all those ships and all those planes in fuel at various points in the Pacific Ocean, it really boggles the mind (and that’s before you even get to the military power wielded by such a force).

It’s become a cliche to refer to that era as ‘The Greatest Generation’, but there’s a lot of truth to it — I doubt if any country anywhere will be able to accomplish anything even approaching that scale ever again.