When Was the Radio Invented?

After emigrating to the U.S. in 1884, Tesla invented the induction coil or Tesla coil, a device essential to sending and receiving radio waves and one the U.S. Patent Office would later say Marconi relied on for his work [source: Britannica].

But in 1895, a fire destroyed Tesla's lab as he prepared to send a radio signal approximately 50 miles (80 kilometers) to West Point, N.Y. [source: PBS].

Meanwhile, Marconi had been conducting his own experiments and in 1896, sent and received Morse code-based radio signals at distances spanning nearly 4 miles (6 kilometers) in England — the first radio communication.

That same year, he applied for, and was granted, the world's first patent in wireless telegraphy in England [source: Nobel Prize].

Tesla applied for his first patents in radio work in 1897 in America. He also built and demonstrated a radio-controlled boat at Madison Square Garden in 1898. Here's where things get sticky in the world of wireless communication.

In 1900, the U.S. Patent Office granted Tesla patents 645,576 and 649,621 (the fundamental design of the Tesla coils) on March 20 and May 15, respectively. Tesla's radio patents gave him ownership over one of the key necessities in radio communications. That same year, on Nov. 10, Marconi filed patent No. 7777, for tuned telegraphy.

At first the patent office denied Marconi's applications on the grounds that his work relied on the use of Tesla coils [source: PBS]. Unfazed, Marconi used his father's connections and wealth to spearhead a profitable business based on his telegraph technology while continuing to pursue his radio patents. In 1901, he transmitted the first transatlantic telegraph.

Marconi reapplied for three years while he gained financial support from company investors Andrew Carnegie and Thomas Edison. Finally in 1904, the U.S. Patent Office inexplicably reversed its earlier decision and gave the Italian the patent for invention of the radio.

Marconi won the Nobel Prize for physics in 1909 [source: Nobel Prize], further fueling the rivalry with Tesla. In 1915, Tesla sued the Marconi Company for patent infringement to no avail. Marconi had won. Or had he?

In an ironic twist of fate, Marconi's company sued the U.S. government in 1943 for patent infringement during World War I. But the case never made it to court.

Instead, to avoid the lawsuit altogether, the U.S. Supreme Court upheld patent 645,576, thus restoring Tesla (who had died a few months earlier) as the inventor of the radio. Nevertheless, many people still tend to think of Marconi as the father of the wireless radio.

The wireless telegraph developed by Marconi, Tesla and others was a far cry from the radio broadcasts we tune into today. So what happened between when the first radio signal was sent out to the proliferation of radio stations we have today?

To transmit signals more complicated than morse code (like a human voice), early radio broadcasting used amplitude modulated (AM) radio. The first AM radio broadcasts were government messages sent out in the early 1900s.

The invention of vacuum tubes brought radio into ordinary people's homes in the 1920s. AM radio waves can travel long distances but are more likely to sound distorted.

Frequency-modulated radio, or FM radio for short, was invented by Edwin Howard Armstrong in 1933. FM radio waves have higher fidelity, meaning they sound closer to the original audio, than AM radio waves.

FM broadcasting eventually became the go-to medium for music, while AM radio remained popular with talk radio shows. That's why you'll typically hear Billboard hits on an FM radio station, not an AM one.