This has been answered numerous times all over the place but the short practical answer is there is no difference in the terms.
Kenpo or Kempo is a large family tree of martial arts. In the US use of the "n" or "m" can tell you something about the lineage of that style... mostly, the "n" styles come out of Parker; and the "n" styles out of Emperado. There are of course exceptions and this is a broad generalization.. but if you want to know more it is easy to find this info.
Kempo - original spelling... Kenpo - spelling after typo made on first publication out of Hawaii in mid-20th century. Too expensive to reprint, so the name stuck.
The Japanese forms use the m too when they Romanise it. It more accurately resembles the sound of the word when spoken in Japanese.
NO, Ryukyu Kempo from Okinawia has nothing to do with that claim. Also there were a few books from the 1920'S that use the term KEMPO. My linage is from Nakamura to Oyata.
4th degree Black Belt in Grandmaster Ed Parker's American Kenpo Karate, under Sifu Refugio Flores. Planning on opening my own Dojo, combining the different styles I have under gone.
I will be starting in AMerican Kenpo..but before that.. when i very first started Kenpo...it was Lama Kenpo Karate..from the style of Lima Lama..i think that's how it's spelled... DJ hunny
kenpo i started with tracys kenpo, then went to parker kenpo that was back in 1965 i teach American chinese kenpo karate www.ackks.com
thank you collin i was going to add that, you beat me to the punch,yep but you are right and the people need to know why things are done the way they are, and why things are spelled the way they are