Key point: The legacy of World Wars II lives on in one way.
For the most part, World War II left the U.S. and Canadian homelands physically untouched. There were a few incidents of sabotage and a few small-scale attacks, such as a Japanese submarine’s shelling of an oil refinery in southern California and balloon bombs launched from Japan that floated over the Pacific and set fires in the western United States and Canada.
But there was nothing to equal the millions of tons of bombs dropped on Britain, Europe, and Japan.
During the war, the United States and its allies dropped 2.7 million tons of bombs on European targets. Some bombs were armed with a delayed fuse so that they would explode hours or even days after they were dropped.
Source: The National Interest