Here is a web site that explains it well http://members.aol.com/analogmike/kraft.htm , I shouldn't plagarise, but I might sum up:
The wah seems to originate from country recordings of the late 5os in which players used their tone controls. After that, pedals started coming out that made it easier to work during performance. It seems that vox was the first company to market the wah successfully, with their pedal being designed by an engineer called Brad Plunkett. However, it also states that other companies such as ampeg wer already experimenting with the idea.
Therefore, the inventor is hard to trace, but it has its roots in country music, and the father of the modern wah is probably Brad Plunkett.
Read the article though, it is quite interesting.
See, ask me more questions, I will go hunting. Maybe I should go on allexperts.com
"Dozens of people spontaneously combust each year, it's just not that widely reported".
