Who invented ADX indicator?

Who exactly is the genius behind the creation of the Average Directional Index (ADX) indicator? Was it a seasoned trader looking to refine their strategies, or perhaps a mathematician with a keen eye for data patterns? The ADX has become a staple in the arsenal of many traders, helping them to identify trends and make informed decisions. But who deserves the credit for this invaluable tool? I'm curious to know the backstory and motivation behind its development.