1941: Happy Birthday, Television!
This day in 1941 marked the first day of commercial television broadcasting. Although "experimental" television had been around since 1939, July 1, 1941 was the day that the Federal Communications Commission licenses went into effect, permitting broadcasters to transmit programs and advertising.
The first channels to receive FCC licenses were New York's WNBT (the precursor to WNBC), operated by the National Broadcasting Company, and WCBW (now CBS) operated by the Columbia Broadcasting System. (The third license was issued to WPTZ — now known as KYW-TV — in Philadelphia.) WNBT's first broadcast image, at 1:30 p.m. ET, was a test pattern. WCBW went on the air one hour later, at 2:30 p.m. ET.
Incidentally, here's TV's first commercial — a 20-second spot advertising Bulova watches. It ran at approximately 2:30 p.m. ET, just before WNBT's coverage of a major league baseball game between the Brooklyn Dodgers and Philadelphia Phillies: