Today is a very important date in the history of radio. On this day in 1901 Marconi ... but let's let Wikipedia tell the story: A major advantage of radio is its ability to provide communication over water. Marconi quickly began to build high-powered stations on both sides of the Atlantic Ocean, in order to communicate with ships at sea (In 1904, a commercial service was established to transmit nightly news summaries to subscribing ocean-going ships, which could incorporate them into their onboard newspapers). At the same time, he was quietly investigating whether it was possible to signal completely across the Atlantic, in order to compete with the transatlantic telegraph cables.
Marconi soon made the stunning announcement that on 12 December 1901, using a 122-metre (400-foot) kite-supported antenna for reception, he had personally received at Signal Hill in St John's, Newfoundland (now part of Canada) signals transmitted by the company's new high-power station at Poldhu, Cornwall. The distance between the two points was about 3,500 kilometres (2,100 miles).
If you wish to read more about the early days of Marconi and radio, here is the link:Guglielmo Marconi - Wikipedia, the free encyclopedia.