1920 KDKA becomes first licensed broadcast station, on the air Nov. 2 at 100 watts.
1921 First World Series broadcast by RCA-owned WJZ: Giants vs. Yankees.
1922 AT&T launches WEAF; becomes first licensed station to sell time to advertisers. 660 kc on the dial. WGY Players in Schenectady perform the first radio drama, "The Wolf" by Eugene Walter, who gets no fee.
1924 First broadcasts of Republican and Democratic conventions. Among the newscasters, Graham McNamee (above) and Norman Brokenshire.
1925 Freeman Gosden and Charles Correll begin broadcasting on WEBH, Chicago (later WMAQ), as "Amos 'n Andy," sponsored by Ipana. "The Grand Ole Opry" begins broadcasting from WSM, Nashville.
1926 Using WEAF as its flagship, NBC becomes America's first radio network.
1927 With 732 stations on air, NAB code of ethics says ads "should not be broadcast between 7 p.m. and 11 p.m." NBC adds second network, the Blue Network, with WJZ as flagship.
1928 William Paley assumes presidency of the failing, 19-station CBS network in September. RCA stock goes from $85 a share to over $500 in seven months.
1930 Advertisers make NBC Red the prestige network; NBC Blue becomes the "second" network. Ad industry groups create Crossley rating service.
1931 BBDO produces "The March of Time" for Time magazine. The Cremo Singer-Bing Crosby-debuts on CBS.
Selected '31 radio ad budgets:
R.J. Reynolds: $1,245,000
Standard Brands: $1,272,000
1932 "One Man's Family" begins 28-year NBC run at San Francisco's KPO.
1933 Robert Trout introduces Franklin Roosevelt's first radio address from White House and coins phrase "fireside chat."
1934 Federal Communication Commission is established by Communication Act. Mutual Broadcasting System formed.
1935 The Hoboken Four appear on "Major Bowes Amateur Hour." Solo singer: Frank Sinatra. "Milkman's Matinee" makes WNEW first 24-hour station with disc jockey format. McCann-Erickson and Nabisco hire unknown bandleader Benny Goodman for its "Let's Dance" program, launching Swing Era.
1937 Mae West appears on "Chase & Sandborn Hour" with Charlie McCarthy and draws censure for "sophisticated" patter.
1938 As Hitler seizes Austria, CBS inaugurates World News Round-Up; Robert Trout anchors the first program with live reports from Vienna (Ed Murrow), and London (William Shirer). Global village begins.
1939 Indiana businessman Wendell Willkie appears on NBC's "Information Please," makes impression and runs for president.
1940 FCC monopoly probe concludes RCA can own only one network. Red remains; Blue is sold and becomes American Broadcasting Co. in 1944. First FM radios manufactured and sold.
1942 Armed Forces Radio Service formed.
Agency reps meet with network and military to (Continued on Page 24)plan D-Day coverage. All commercials to be suspended. George Hicks' description of Normandy battle breaks network embargo on recordings.
1945 Norman Corwin writes and directs "On a Note Of Triumph" for V-E Day. Becomes all-time radio masterpiece, as does "14 August" on V-J Day. FCC changes FM frequency position, making all FM receivers obsolete.
1946 Bing Crosby moves from NBC to ABC in order to pre-record on magnetic tape.
1948 William Paley lures Jack Benny to CBS from NBC.
1950 Publication of "Red Channels"; Sponsors and agencies surrender in panic to blacklisting.
1952 FCC lifts freeze on TV licenses; microwave transmitters deliver programs coast to coast.
1955 To stem network slide, Pat Weaver creates "NBC Monitor Radio," a weekend news magazine format that runs for nearly 20 years.
1960 "Amos 'n Andy" and remaining soap operas leave the air; radio becomes driven by pop record air play; networks survive providing news/features.
1962 First communication satellite, "Telestar," is launched."
1968 ABC creates four networks to serve growing format fragmentation among affiliates.
1970 As advertisers target smaller audiences, new stations seek licences. Stations double to 10,000 by 1990. National Public Radio launches "All Things Considered."
1973 "CBS Mystery Theater" begins decade-long nightly run.
1977 Amway buys Mutual, launches Larry King on 28 stations in 1978. Mutual has 950 affiliates by '82. Syndication technology begins shift from phone lines to satellite.
1982 ABC buys Casey Kasem's "America's Top 40" and "Country Countdown" from Watermark syndication.
1986 "Steve Allen Show" a daily program and the last great swan song before NBC's sale to GE in '88 and final breakup.
1987 Edward F. McLaughlin forms EFM Media Management; In June '88, launches Rush Limbaugh in joint EFM-ABC venture.
1988 Emmis Broadcasting buys WNBC, the lineal descendent of WEAF and WRCA, New York, and moves Sports Radio WFAM to the legendary 660 kc position. Purchased by Infinity in 1992.
1992 Westwood One syndicated Gordon Liddy, latest in growing trend toward right-wing talk shows.
1995 Tom Snyder returns to TV in January with a rare contract stipulation: His show becomes the first daily commercial TV-radio simulcast since the days of Arthur Godfrey.