The story of radio begins with the telegraph and the solution of a crime. The telegraph was first installed on the UK's revolutionary Great Western Railway. Engineered by I. K. Brunel and based, unlike every other railway, on the broad gauge of 7 feet and 1/4 inch the GWR (also known as God's Wonderful Railway) was founded in 1835 and began running trains in 1838. The control of trains was a constant problem and the telegraph was installed in 1839 along the first 13 miles of track between London Paddington and the station at West Drayton. The system spread along the rest of the GWR and in 1845 was used to alert the police to the departure of John Tawell, a man who was accused of murdering his mistress and had simply boarded a train to make his escape. Tawell was caught, arrested and later hanged, an event which confirmed the popularity of the telegraph, but there was one major weakness in the system; the telegraph needed wires to be laid between stations.
Wireless communication had been around since 1880, when Alexander Graham Bell, inventor of the telephone (which requires wire) invented a wireless communications device in the from of the photophone. This method of communication sent sound along a beam of light, however as the laser and associated technology had not been invented, the photophone was dependent on sunlight, few understood the significance of the discovery and no real applications were possible.
At around the same time David Edward Hughes, inventor of the telegraph was sending and receiving radio waves, but it was not clear what was happening or why and his work was not published until 1889. Electromagnetic radiation had been predicted by the work of Michael Faraday and James Clerk Maxwell but it was not until the experiments of Heinrich Hertz in 1888 that electromagnetic waves were shown to be sent and received by experimental apparatus. Hertz did little to enlarge on his experiments, again not understanding their significance, in fact he denied that his discoveries had any practical application other than to prove Maxwell had been right.
David Hughes' radio waves and Bell's sunbeams are both forms of electromagnetic radiation but it was left to others to build some practical apparatus to make use of the discovery. This was done by several scientists working at the same time, most notably Nikola Tesla, J C Bose, Ferdinand Braun and Alexander Popov. But one name above others is remembered in regard to radio, and that is Marconi.
Working in the late 1890's Marconi demonstrated the transmission of communication via radio waves using apparatus which was very similar to that built and described by Tesla. He went on to obtain patents and install radio on ships and to broadcast across the Atlantic, succeeding in 1902. In 1903, on the 18th of January, President Theodore Roosevelt became the fist American to send a transatlantic greeting by wireless to King Edward VII in the UK. Marconi later shared the Nobel prize for Physics with Karl Braun for their work on the radio sciences.
A few years later, in 1910 Dr Hawley Crippen murdered his wife and set off with his mistress for Canada aboard the SS Montrose. The Captain noticed that Crippen's mistress was not what she seemed (she was disguised as a boy) and watched the couple, eventually sending a wireless telegram from the ship to the police. Chief Inspector Walter Dew of Scotland Yard then boarded a faster ship and arrived in Canada ahead of Crippen, boarding the Montrose in the guise of pilot. He arrested Crippen on board.
The story, and the role played by radio, once again enabling the arrest of a murderer, cemented the role of radio in the public imagination. Rudimentary crystal radios could be bought and built by everyone and the popularity of radio was assured. Following World War II The Federal Communications Commission began to designate certain 'bands' or specific ranges of wavelengths for use by the public, while others were devoted to the government, the military and the emergency services. In addition to long range radio operations a waveband was set aside for short range use by the general public.
The rest as they say, is history. That service grew to be CB Radio.