Its first broadcast was on July 18, 1922. It was originally assigned the frequency of 350 kHz. On May 16, 1925, the first broadcast of the Kentucky Derby was broadcast over WHAS and WGN. During the 1937 Flood the station aired 115,000 messages. On March 29, 1941 the station moved to its current frequency of 840 AM. On March 30, 1970 WHAS began 24-hour operation. WHAS' music format was for many years an adult-oriented combination of Top 40 hits and Oldies; one longtime slogan was "Good and Gold" (as in "good music", or adult contemporary/MOR, and "golden" oldies). The station continued to feature some music programming (mostly of the oldies variety) well into the 1990s, making it one of the last 50,000-watt clear-channel radio stations to feature music programming on a regular basis.
The station has been broadcasting on a full time basis in the IBOC digital radio mode, using the HD Radio system from iBiquity, since September 2007 after an initial testing period which started in 2006. Prior to 1995, WHAS had been broadcasting in AM stereo, and was the last 50 kW AM station with a full time Adult Contemporary format.
The station was originally part of the local media empire ruled by the Bingham family, which also published Louisville Courier-Journal (now owned by Gannett) and owned television station and CBS turned ABC affiliate WHAS-TV (owned by Belo now).
WHAS is the flagship radio station of the annual WHAS Crusade for Children telethon. The station also broadcasts The Moral Side of the News, one of the oldest public affairs programs in American broadcasting, dating back to the 1940s. The show has also been shown on WHAS-TV since the 1950s. The show's panel of clergy members have been involved in distributing the proceeds of the Crusade for Children among local charities since the telethon's beginning.
WHAS was the first station to broadcast the call of the Kentucky Derby live, using an announcer who watched from the windows of one of the famous twin spires of Churchill Downs.
WHAS is currently owned by Clear Channel Communications.
WHAS is the flagship station for University of Louisville athletic broadcasts, carrying Cardinal football and men's basketball games.
In the hours immediately following the storm, the station delivered important information about what areas had been directly impacted by the storms, and traffic reporter Dick Gilbert followed the tornado in his helicopter, reporting on the damage as he flew at a safe distance behind the storm.
The station stayed with continuous coverage of the disaster until well into the early morning hours of April 4. For their efforts, the station's personnel earned thanks from then-Kentucky Governor Wendell Ford and President Richard Nixon.