But an annotated script of the film, to be sold at auction next month, shows that because of censorship rules on swearing, the line was nearly changed to: "Frankly my dear, I just don't care."
The "rainbow script", typed on pink and cream paper with the changes attached in blue, was usually thrown away after the final version had been retyped on plain paper. This one is expected to fetch at least pounds 40,000 when sold at Sotheby's in New York.
Eric Alberta, who catalogued the sale which includes David O Selznick's 1939 Best Picture Oscar for the film, said the script was an extraordinary piece of Hollywood memorabilia. "Rainbow scripts are extremely rare and this is the first one I have seen," he said.
This one belonged to Lydia Schiller, the script clerk to Selznick, and contains the following notes from the continuity director, Barbara Keon: "This supersedes my note of June 6 on the alternate speech for Scene 681. Please instead make two alternate ends to this scene besides the corrected version Mr Selznick and Mr Fleming devised on the set yesterday. The speeches for the alternate version will read:
"1. Rhett: (very slowly) `Frankly my dear I just-don't-care.'
"2. `I wish I could care what you do or where you go - (he opens the door) But frankly my dear I just don't care.' These are for censorship protection."
Mr Alberta said: "A lot of people collect by genre or costume or period, but Gone with the Wind is one of the few films which has its own dedicated collectors and this script is a hallowed part of the legend. "If you whisper the words `rainbow script' to collectors they hold it in awe."
Gone with the Wind took three years to reach the big screen because Selznick was determined to make the best movie ever. Margaret Mitchell's book was a best-seller in 1936 and Selznick wanted to make a film faithful to the original. His hunt for the perfect Scarlett is legendary - he saw 1,400 hopefuls and screen-tested 90 others before he found Vivien Leigh.
And the script alteration suggestions? Selznick simply paid the board of censors $5,000 and the original line was allowed to remain.