“The Oprah Winfrey Show” left local Chicago television and launched into national syndication on September 8, 1986, distributed by King World Productions. Within a matter of years it became the highest-rated talk show in American television history, reaching an estimated weekly audience of 46 million viewers in the U.S. by 2008.

Key Points

• The show’s national debut came on September 8, 1986, at the urging of film critic Roger Ebert, according to History.com’s dated account of the launch.
• King World Productions, run by brothers Roger and Michael King, handled the syndication deal. TVWeek reported Michael King’s own explanation for signing her: “The daytime talk show was then dominated by Phil Donahue. We wanted someone different. Oprah Winfrey was doing a great job hosting `AM Chicago,’ and it goes without saying that she looked different.”
• The show quickly displaced Donahue as the dominant daytime host and became, in King’s words to TVWeek, “a national phenomenon.”
• By 2008, the program aired in 134 countries and drew an estimated 46 million U.S. viewers a week, per History.com — a run built on a ratings peak Wikipedia’s sourced history puts at 12.6 million daily viewers during the 1991-1992 season.
• The show collected 47 Daytime Emmy Awards before Winfrey stopped submitting it for consideration in 2000, according to Wikipedia’s documented awards history.
• “The Oprah Winfrey Show” ended its run in May 2011, per History.com, after 25 seasons on the air.

The scale of that national launch is easy to undersell in hindsight. Daytime talk in 1986 was still built around a single dominant format that Phil Donahue had defined for more than a decade, and King World’s bet on syndicating a local Chicago host to stations nationwide was, by the Kings’ own account to TVWeek, a deliberate swing at doing something different rather than a guaranteed hit. History.com’s coverage also credits the show with originating what became known as the “Oprah Effect” — the pattern by which a single on-air recommendation from Winfrey could turn a book, product, or film into an instant bestseller, a level of consumer influence few television hosts before or since have matched.

Four decades later, the syndication model King World bet on in 1986 is still the basic structure most daytime talk shows use to reach a national audience, and Winfrey’s run remains the benchmark other hosts in the format are still measured against. King World itself wasn’t a newcomer to that kind of bet — the same company had already built its business syndicating “Wheel of Fortune” and “Jeopardy!” nationally before taking a chance on a daytime talk format, per TVWeek’s account of the company’s history, which makes the Oprah deal less an outlier than the continuation of a pattern the Kings had already proven could work.