Vladimir Kosma Zworykin is sometimes hailed as 'the father of modern television'. He filed two patents in 1923 which formed the basis of what became “television”.
However it was not until the Radio Corporation of America (RCA), unveiled a display of its first TV sets for sale to the American public at the World's Fair. For nearly all Americans in 1939, seeing pictures in motion on a small screen was a novelty in the spring of 1939, and a source of wonder. Some people just stared at the screen of the TV set on display. Others seeing TV for the first time that day, exclaimed, "I never thought it would be like this. Why, it's beyond conception, and here it is."
Not only was RCA showcasing its new TV sets, the company was also starting the nation's first schedule of TV programs by televising the Fair's opening day. Shortly after noon RCA's telecast began with a live picture of the World's Fair centerpieces, two futuristic structures called the Trylon and Perisphere, under a bright springtime sun that darted between clouds. Seated in front of an RCA television set in Manhattan, eight miles from the Fair, a viewer told a reporter, "I could tell when the sun went behind a cloud." Other viewers watched the telecast on a dozen sets in the RCA Building and on another hundred or more TV sets scattered about the New York area.
This first TV audience next saw a parade marching through the Fair's center court. TV viewers saw New York's Mayor Fiorello LaGuardia walks up to the platform and look directly into the lens of the camera. Apparently, LaGuardia looked good on TV. The next day's New York Times called him "the most telegenic man" in the city, describing "the violent emphasis in the toss of his head and the dramatic facial expressions" that the Times reporter had watched on TV in Manhattan.
President Franklin D. Roosevelt also appeared on live TV that afternoon; he was the first President to do so. He rode a limousine into the Fair after the parade and later gave the speech that officially opened the Fair to the public.
For more information on this subject visit the FCC's Television Technology - A Short History