Hiram Percy Maxim was a graduate of the Massachusetts Institute of Technology as a Mechanical Engineer. He is noted as the inventor of the "Maxim Silencer" for explosive weapons as well as his invention of silencers for gasoline engines.
He created the ARRL in 1914 because of his seeing a need to build up an organized group of "Relay" stations to pass messages via amateur radio. This allowed messages to pass further than any particular station of the time could reach.
His father was Sir Hiram S. Maxim, inventor of the Maxim Machine gun.