Where did the term “assault weapon” (not “assault rifle”) originate from?

Answer 1

I'm not sure, but here's a guess.

There used but troops the storm buildings. So I guess that came to refer to the guns they use. Short barreled, but rapid fire. As opposed to long barreled and slow firing, but accurate a long distances.

When applied to all weapons, they're known for portability and ease of operation, by one person.

Answer 2

Big Ernie at the bowling alley said it was Wally at the fillin' station who started that