Gone with the Wind is a 1939 romantic epic about Scarlett O'Hara, an indomitable and ruthless Southern Belle, stretching from just before The American Civil War through much of the Reconstruction era. Adjusted for inflation, it is the highest-grossing movie of all time.
Both the source novel and the studios of The Golden Age of Hollywood tended to romanticize the South, and so this is one of the most romantic films ever made whether you want it to be or not. Still, the movie was somewhat progressive for its time — it gave several roles to African American actors when Hollywood was trying its best to push them out, and Hattie McDaniel's win for Best Supporting Actress was the first Oscar given to a black person.
Produced by David O. Selznick and filmed between December 1938 and November 1939 (having been in development since just after the book's publication in 1936) and released in December 1939 in glorious Technicolor, it starred Vivien Leigh as Scarlett and Clark Gable as Rhett. Interestingly, director Victor Fleming was also the director of another legendary Technicolor film from that year — The Wizard of Oz.
The original novel was written by Margaret Mitchell, and its massive popularity naturally led to demands for a sequel. In 1991 Mitchell's estate licensed Alexandra Ripley to write the continuation novel Scarlett, which was adapted into a CBS miniseries three years later. There's also two licensed prequels - Rhett Butler's People, telling the original story from Rhett's perspective, and has a different ending to Scarlett, and Ruth's Journey, about the life of Ruth, aka "Mammy". Then there was the unofficial sequel The Winds of Tara, which was published in Australia to get around copyright law. Bear in mind that this has another ending for those who are not happy with Scarlett or Rhett Butler's People. And finally, there is Alice Randall's The Wind Done Gone, written in African-American Vernacular English from the point of view of Scarlett's mixed-race half-sister Cynara, whom she never notices in the original novel, and whom Rhett himself takes as a lover. The Mitchell estate sued Randall, but the case was dropped when the court ruled it was protected under the First Amendment as a Parody. (In the strict legal sense as a commentary on the original. It is very much not a comedy.) Notably, none of the original book's characters are explicitly named, only referred to by initials and nicknames.
It is Ted Turner's favorite movie, and it was the first broadcast program on both TNT and TCM; a theater at the CNN Center also played it for many years until it was taken out and replaced by additional newsroom space for CNN's web operations.
In 2008, a musical production ran on the West End in London. It was savaged by the critics and closed early.
After the film's 80th anniversary, three of the original cast members are still alive: Olivia de Havilland, Mickey Kuhn (Beau Wilkes at age 6) and Patrick Curtis (baby Beau Wilkes).