The Ozone layer, which mostly lies on the lower portion of the stratosphere.
How Long Did The Vietnam War Last. The Vietnam War is the longest war ever to have taken place in the American history. It lasted for 16 years and it was terrible for the Americans at that time as the Civil Rights campaign was at its peak and so also the Vietnam War and anti war protests.
It will be America's longest war by quite some years. It's truly remarkable when you think about it. The Vietnam War may have defined 1960s and 1970s America, but it lasted 10 years by the most widely accepted metric (and, officially, it was never a war at all). And while World War I and II may have killed far more American troops, the fighting didn't linger for a decade and a half.