1940 Guitar Pedals

Yes there actually was a guitar pedal before their was mass produced electric guitars how crazy is that ! Before the Fender Stratocaster, Les Paul, Broadcaster there was the DeArmond Trem Troll 800 that was released as early as 1946 but most facts put it as released 1948. The way it worked it sent the signal from the guitar through an electrostatic fluid (Mercury) that was moving in a motorized cylinder, there by cutting off and delaying the signal. From this the first Tremolo was invented and produced for electric guitar, even the accordion ! But in another 5 years Electric Guitar production and amp's caught up to the Tremolo pedal, and soon that they would be in every Fender Amp past the Champ and Deluxe model. The Fender amp tremolo was an electric tube circuit with no mechanical movement like the DeArmond. 

Here is the first picture of the DeArmond Trem Troll 800 tremolo pedal you see the control unit, that had the fluid in it and the control. The second picture shows the whole unit with the controller pedal as is also seen in the video below