What’s My Line? is a panel game show which originally ran in the United States on the CBS Television Network from 1950 to 1967, with several international versions and subsequent U.S. revivals.  The game tasks celebrity panelists with questioning contestants in order to determine their occupations.  It is the longest-running U.S. primetime network television game-show.  Moderated by John Charles Daly and with panelists Dorothy Kilgallen, Arlene Francis, and Bennett Cerf, What’s My Line? won three Emmy Awards for “Best Quiz or Audience Participation Show” in 1952, 1953, and 1958 and the Golden Globe for Best TV Show in 1962.

Produced by Mark Goodson and Bill Todman for CBS Television, the show was initially called Occupation Unknown before deciding on the name What’s My Line?.  The original series, which was usually broadcast live, debuted on Thursday February 2nd, 1950 at 8:00 p.m. ET.  After airing alternate Wednesdays, then alternate Thursdays, finally on October 1st, 1950, it had settled into its weekly Sunday 10:30 p.m. ET slot where it would remain until the end of its network run on September 3rd, 1967.  The show was produced at CBS Studio 52 and, towards the end of its run, at CBS’ Studio 50 (now the Ed Sullivan Theater) in Manhattan.

The original series was hosted (called the moderator at that time) by veteran radio and television newsman John Charles Daly.  Clifton Fadiman, Eamonn Andrews, and Bennett Cerf substituted on the four occasions Daly was unavailable.
The show featured a panel of four celebrities who questioned the contestants.  On the initial program of February 2nd, 1950, the panel was former New Jersey governor Harold Hoffman, columnist Dorothy Kilgallen, poet Louis Untermeyer, and psychiatrist Richard Hoffmann.  For the majority of the show’s run the panel consisted of Kilgallen, Random House publisher and co-founder Bennett Cerf, actress Arlene Francis and a fourth guest panelist.  During the show’s earliest period the panel generally consisted of Kilgallen, Francis, Untermeyer and comedy writer Hal Block with Cerf replacing Untermeyer in 1951 and comedian Steve Allen replacing Block in 1953.  Steve Allen left to launch The Tonight Show in 1954 and was replaced by comedian Fred Allen who remained on the panel until his death in 1956.  After Kilgallen’s death in 1965 the two remaining seats on the panel were never filled regularly again.  The most frequent guest panelist was Arlene Francis’ husband Martin Gabel, who appeared 112 times.
Regular announcers included Lee Vines (1950–1955), Hal Simms (1955–1961), Ralph Paul (1961), and Johnny Olson (1961–1967).

What’s My Line? was a guessing game in which four panelists attempted to determine the line (occupation), or in the case of a famous “mystery guest,” the identity, of the contestant. Panelists were required to probe by asking only questions which could be answered “yes” or “no”.  A typical episode featured two standard rounds (sometimes a third, and very rarely a fourth) plus one mystery guest round.  On the occasions on which there were two mystery guests, the first would usually appear as the first contestant.

For the first few seasons, the contestant would first meet the panel up close, for a casual “inspection”, and the panel was allowed one initial “wild guess.”  However, beginning in 1955 Daly simply greeted, then seated the contestant who instead met the panel at the end of the game.  The contestant’s line was then revealed to the studio and television audiences, and Daly would tell the panel whether the contestant was salaried or self-employed, and later in the series, dealt in a product or service.
A panelist chosen by Daly would begin the game.  If he received a “yes” answer he continued questioning, but if he received a “no,” questioning passed to the next panelist and $5 was added to the prize.  The amount of the prize was tallied by Daly who flipped one of 10 cards on his desk.  A contestant won the top prize of $50 by giving ten “no” answers, or if time ran out, with Daly flipping all the cards.  As Daly occasionally noted, “10 flips and they (the panel) are a flop!”  Daly later explained, after the show had finished its run on CBS, the maximum payout of $50 was to ensure the game was played only for enjoyment, and that there could never be even the appearance of impropriety.  Later in the series, Daly would throw all the cards over with increasing frequency and arbitrariness, evidence the prize was secondary to game play.
Panelists had the option of passing to the next panelist—or even disqualifying themselves entirely if they somehow immediately knew what the contestant’s occupation was, sometimes by virtue of having seen that contestant before—and they could also request a “conference,” in which they had a short time to openly discuss ideas about occupations or lines of questioning.
Panelists adopted some basic binary search strategies, beginning with broad questions, such as whether the contestant worked for a profit-making or non-profit organization, or whether the product was alive (in the animal sense), worn, or ingested.  To increase the probability of “yes” answers they would often phrase questions in the negative starting with “Is it something other than…” or “Can I rule out…”
The show popularized the phrase “Is it bigger than a breadbox?”, first posed by Steve Allen on January 18th, 1953 then refined over subsequent episodes.  Soon, other panelists were asking this question as well.  On one occasion the guest was a man who made breadboxes. It was correctly guessed by Allen after Kilgallen asked “Is it bigger than a breadbox” and Daly could not restrain his laughter.

The final round of an episode involved blindfolding the panel for a celebrity “mystery guest” (originally called “mystery challengers” by Daly) whom the panel had to identify by name, rather than occupation.  In the early years of the show, the questioning was the same as it was for regular contestants, but starting with the April 17th, 1955 show, panelists were only allowed one question per turn.  Mystery guests usually came from the entertainment world, either stage, screen, television or sports.  When mystery guests came from other walks of life, or non-famous contestants whom the panel but not the studio audience might know, they were usually played as standard rounds.  However, the panel might be blindfolded, or the contestant might sign in simply as “X”, depending on whether he would be known by name or sight.
Mystery guests would usually attempt to conceal their identities with disguised voices, much to the amusement of the studio audience.  According to Cerf, the panel could often determine the identity of the mystery guest early, as they knew which celebrities were in town, or which major movies or plays were about to open.  On those occasions, to provide the audience an opportunity to see the guest play the game, the cast would typically allow questioning to pass around at least once before coming up with the correct guess.
Sometimes, two mystery guest rounds were played in an episode, with the additional round usually as the first round of the episode.
What’s My Line? is known for its attention to manners and class.  In its early years, business suits and street dresses were worn by the host and panelists, but by 1953, the men wore black suits with bow ties (a few guests in fact wore tuxedos) while female panelists donned formal gowns and often gloves.  Exceptions to this dress code were on the broadcasts immediately following the deaths of Fred Allen and Dorothy Kilgallen, in which the male cast members wore straight neckties and the women ordinary dresses instead of evening gowns.

Often Daly would need to clarify a potentially confusing question, but his penchant for verbose replies often left panelists more confused than before (which Danny Kaye once parodied as a panelist).  On more than one occasion, Daly “led the panel down the garden path” – a favorite phrase used when the panel was misled by an answer.

To begin a round, Daly would invite the contestant to “come in and sign in, please” which by 1960 evolved to the more familiar “enter and sign in, please.”  The contestant entered by writing his or her name on a small sign-in board.  Daly would then usually ask where the guest lived and, with a woman, if she should be addressed as “Miss” or “Mrs.” Early in the show’s run, the panel was allowed to inspect contestants, studying their hands, or label on their suit or asking them to make a muscle.
While ostensibly a game show, if there was time, it was also was an opportunity to conduct interviews.  Line’s sister show, I’ve Got a Secret (and later the syndicated version of WML) engaged in the practice of contestants’ demonstrating their talents.  However, despite frequent requests by the panel (particularly Arlene Francis) such demonstrations rarely occurred as according to executive producer Gil Fates, Daly was not fond of this practice.

After the first four episodes, the show gained its initial sponsor: Stopette spray deodorant made by Jules Montenier, Inc.  This involved featuring the product in the show’s opening, on the front of the panel’s desk, above the sign-in board, and on Daly’s scorecards.  Bennett Cerf explained that Dr. Montenier was ultimately ruined by his refusal to abandon or share sponsorship as the show entered new markets and became too expensive.  After Dr. Montenier sold Stopette to Helene Curtis, the series was sponsored by a variety of companies which were either regular or rotating. Sponsors were accorded the same exposure on the set as Stopette.  Near the end of its run, sponsors would be introduced in the opening title and given commercials during the show, but would not be displayed on the set.
Unknown to the public, mystery guests were paid $500 as an appearance fee, whether they won or lost the game.  This was in addition to the maximum $50 game winnings, which guests sometimes donated to charity.  Guest panelists were paid $750 as an appearance fee.  The regular panelists were under contract and were paid “much more,” according to Fates. Bennett Cerf explained that when he became a permanent member of the program, he was paid $300 per week, and by the end of the series, they were being paid “scandalous amounts of money.”
From 1950 to 1966, the game show was broadcast in black-and-white, as was typical of most game shows at the time.  But by 1966, prime-time programs on all three networks started broadcasting in color.  After the show ended in 1967, CBS replaced the color videotapes with the kinescope versions instead for syndication.  As a result of this change, the 1966-1967 episodes of What’s My Line? were only shown in black-and-white after the show ended.

CBS announced in early 1967 that a number of game shows, including What’s My Line?, were to be canceled at the end of the season.  Bennett Cerf wrote that the network decided that game shows were no longer suitable for prime time, and that the news was broken by the New York Times before anyone involved with the show was notified.

The 876th and final CBS telecast of What’s My Line? aired on September 3rd, 1967; it was highlighted by clips from past telecasts, a visit by the show’s first contestants, and the final mystery guest, who was John Daly himself.  Daly had always been the emergency mystery guest in case the scheduled guest was unable to appear on the live broadcast, but this had never occurred.  Mark Goodson, Bill Todman and Johnny Olson appeared on-camera as well.