For many years, NBC was closely identified with David Sarnoff, who used it as a vehicle to sell consumer electronics. RCA and Sarnoff had captured the spotlight by introducing all-electronic television to the public at the 1939–40 New York World's Fair, simultaneously initiating a regular schedule of programs on the NBC-RCA television station in New York City. President Franklin D. Roosevelt appeared at the fair before the NBC camera, becoming the first U.S. president to appear on television on April 30, 1939 (an actual, off-the-monitor photograph of the FDR telecast is available at the David Sarnoff Library). The broadcast was transmitted by NBC's New York television station W2XBS Channel 1 (later WNBC-TV; now WNBC, channel 4) and was seen by about 1,000 viewers within the station's roughly coverage area from its transmitter at the Empire State Building.