The first radio was initially called the "wireless telegraphy," and a complete functional model was built by Guglilmo Marconi in 1895. Several other inventors laid the groundwork for the invention including Heinrich Rudolf Hertz, Nikola Tesla, Amos Dolbear, Reginald Fessenden and William Crookes.
Marconi went on to establish three companies named American Marconi, British Marconi and Canadian Marconi; these companies imposed a ban on using his invention to communicate with rival technologies.
Orders for his radio rose in the aftermath of a preventable boat tragedy. This led Marconi to open a factory dedicated to building radios in Chelmsford in 1912. During this time, amateurs and hobbyists started broadcasting using improvised equipment. When the United States joined World War II, it imposed a ban on all amateur radio stations and recruited the operators into the army.