The WGN radio station went on the air on June 1, 1924. They took over their frequency from an even earlier radio station, WDAP, which went on the air in May of 1922. The call letters were said to stand for "World's Greatest Newspaper", in reference to the station's owner, the Chicago Tribune.
WGN was a high powered clear channel station, at night time often audible over much of the USA and sometimes as far away as Australia and South America. Early programing was noted for its creativity and innovation; it included live music, political debates, comedy routines, and some of radio's first broadcasts of sporting events, including the Indianapolis 500 automobile race. In 1926 WGN broadcast Sam & Henry, often considered the very first situation comedy.
WGN is now a news and talk radio station.
WGN-TV Television began test broadcasts in February of 1948 and began regular programing the following month.
WGN-TV is now the Chicago affiliate of the Warner Brothers television network. WGN-TV also broadcasts their programming (sans the WB shows) via satellite to DirectTV, DishNetwork and cable television subscribers around the United States elevating it to a Superstation status.
On November 22, 1987, during the 9 O'Clock News sportscast WGN's broadcast signal was hijacked by an unknown person wearing a Max Headroom mask for approximately 25 Seconds, This was the first incident that night involving the interruption of a television station's broadcast signal. Approximately 2 hours later, Chicago PBS station WTTW-TV Channel 11 had their broadcast interrupted by the same person. WGN's transmitter is atop the John Hancock building and engineers were almost immediately able to thwart the video hacker by changing the Studio To Transmitter frequency cutting them off. Unfortunately for WTTW whose transmitter is atop the Sears Tower they were unable to stop the hacker and were forced to endure almost two minutes of the hacker.