You have to remember we just had a war with Japan, and Karate was a very popular sport in Japan. The term Karate came to mean asian Martial Arts in the mind of your average American. So the question became,"what style of Karate do you study?". And the answer is of course Kempo or Kenpo. These words are derived from "chuan fa", or hand of china. In Japanese Kempo means Law of the fist, or more precisely, the parameters defining how you use your fists. Our parameters are defined by Ed Parker; so, Ed Parker's American Kenpo Karate means, Your method of using your fists and your emty hands, with parameters defined by Ed Parker. Or more commonly said Law of the Fist and the emty hand.
Sean