KYW (Radio station : Chicago, Ill.)

The Westinghouse station was first licensed on November 15, 1921, as Chicago's first broadcasting outlet, with the randomly assigned call letters of KYW. At first, it was jointly operated by Westinghouse and Commonwealth Edison, with Westinghouse later taking over as sole operator. Through the financial support of Samuel Insull, and the cooperation of Mary Garden, director general of the Chicago Opera Company, KYW's initial broadcasts consisted of the opera company's entire six-day-a-week winter season schedule. KYW was the first station to broadcast live opera.

In 1922, KYW became affiliated with the Chicago Evening American newspaper. They were to provide news, market, and stock reports. Radio news became a daily part of KYW's broadcasting programming. By 1923 the station introduced the "World Crier" service which broadcast on the hour and half-hour, 24 hours a day. It gave listeners information about national and world events. This service was discontinued in 1927 due to scheduling problems.

The station was also one of the pioneers of sports broadcasting. The station broadcast its first baseball game on April 22, 1922, giving listeners a play by play account of the opening game of the series between Chicago and Cincinnati at Cincinnati. The broadcast of the Marron-Northwestern football game on Saturday, October 14, 1922, directly from Staff Field in Chicago, was the first football game ever broadcast in the area.

On September 1, 1928, the Federal Radio Commission (FRC) ordered that the operations of Westinghouses' three stations should be consolidated. WEBH was deleted, and the other two stations were merged, with a dual call letter assignment of KYW-KFKX, although the latter call sign would be rarely if ever used after 1930. On May 15, 1933, after the FRC requested that stations using only one of their assigned call letters drop those that were no longer in regular use, KFKX was eliminated and the station reverted to just KYW.

In July 1932, under the Davis Amendment, it was determined that KYW would move from Chicago, IL to Philadelphia, PA. After broadcasting its last program in Chicago on December 2, 1934, KYW aired its debut Philadelphia program the next day. Westinghouse used the studios and sales operations of WCAU. The move made KYW the easternmost U.S. radio station with a call sign beginning with "K". When KYW moved to Philadelphia, it changed from NBC Blue to NBC Red, predecessor of modern-day NBC, an affiliation it maintained during the remainder of the 1930s and throughout the 1940s.

On March 29, 1941, KYW's clear channel assignment was shifted from 1020 to 1060 kHz, its current frequency, as part of a nationwide adjustment of assignments engineered by the North American Regional Broadcasting Agreement (NARBA). In 1942, KYW added an FM station at 45.7 megacycles, W57PH. It largely simulcast KYW's programming and later moved to 92.5 MHz as KYW-FM when the FM dial was shifted. But development of FM radio was slow and Westinghouse decided to shut down KYW-FM in mid-1954; the equipment was donated to the Delaware Valley Educational Television Corporation and the Philadelphia Board of Education.

In June 1955 Westinghouse agreed to trade KYW and WPTZ to NBC in exchange for NBC's Cleveland properties, WTAM-AM-FM and WNBK television. NBC had to receive a waiver for the swap because KYW and NBC Radio's New York City flagship, WRCA (now WFAN) were both clear channel stations. At the time, the FCC normally did not allow common ownership of clear channel stations with overlapping nighttime coverage. After clearing the final regulatory hurdles, the swap went into effect on January 22, 1956.

On February 13, NBC changed KYW's call letters in Philadelphia to WRCV (for the RCA-Victor record label). At the same time, Westinghouse changed the call letters of its new Cleveland station from WTAM to KYW. The Westinghouse-NBC station swap, and its subsequent reversal nine years later, resulted in two alternate ways to recount KYW's history. In the records of the FCC, the station in Philadelphia on 1060 kHz merely underwent two call letter and ownership changes, taking place in 1956 and 1965. However most KYW histories follow the path of the call letters, and refer to KYW moving from Philadelphia to Cleveland in 1956, then returning to Philadelphia nine years later.

Almost immediately after the NBC-Westinghouse trade was finalized, Westinghouse complained to the FCC and the United States Department of Justice that it had been coerced into making the station swap, including a threat by NBC to revoke Westinghouse's NBC-TV affiliations. A lengthy investigation was launched. The Commission renewed NBC's licenses for WRCV radio and television, on the condition that the 1956 station swap with Westinghouse be reversed. Following nearly a year of appeals by NBC, Westinghouse regained control of WRCV-AM-TV on June 19, 1965, and subsequently restored the KYW call letters to the radio station. The television station became KYW-TV at this point.

On September 21, 1965, shortly after Westinghouse regained control of 1060 AM, the newly revived KYW dropped its NBC radio affiliation. It became one of the first radio stations in the country to switch to an all-news radio format. KYW has long been a leader in the Philadelphia radio market, although its audience had naturally reduced due to the decline of AM as a whole.

In 1995, Westinghouse Electric announced its purchase of CBS. Upon its completion KYW became a sister station to its long-time rival, CBS-owned WGMP (1210 AM, now WPHT). In November 2017, CBS Radio merged with Entercom, which is based in Philadelphia. Entercom had never previously owned a station in its home market. The transaction separated KYW from its television counterparts, and marked the first time since its establishment 96 years earlier that KYW was no longer owned by a direct descendant of Westinghouse.

KYW radio ended its longtime partnership with KYW-TV on February 10, 2020, and began broadcasting traffic, news, and weather information from NBC-owned WCAU (channel 10). KYW broke from its all-news format on November 3, 2022, to simulcast Game 5 of the 2022 World Series, which involved the Philadelphia Phillies, with WPHT. The Phillies' flagship station, WIP-FM (94.1), could not air the game because of a conflict with the Philadelphia Eagles, who were playing a Thursday Night Football game coincidentally in Houston.