To show their enemies, USA and much of the west, that they were capable of producing atomic bombs and even using them.
Actually why argue about the speed limit. It is there for everyone's protection. It is there for a good reason. So why argue about it? Yes some people don't follow it. But that is the job of a police officer not of some kids in 6th grade. My point is don't argue against it argue for it.
The Lewis and Clark Expedition
