Love letters between the actress and Joe DiMaggio, Arthur Miller and others will go up for sale next month at an auction by Julien's Auctions of Beverly Hills.
Among the items being flogged at the December 5-6 sale will be some handwritten notes from baseball star, Joe DiMaggio who once was fleetingly married to the actress and agonised for her to return to him once she file for divorce in 1954.
"I love you and want to be with you," DiMaggio said in one pained note to Monroe, written when she announced she leaving him after just of months of matrimony. "There is nothing I would like better than to restore your confidence in me."
In another correspondence, addressed to "Mrs. Joe DiMaggio", the Yankees great writes about the sadness he felt when Marilyn tearfully confirmed the separation during a television appearance.
"My heart split even wider seeing you cry in front of all these people," he wrote.
The collection also include letters from such famous friends as Clark Gable, Cary Grant and Jane Russell – Russell allegedly wrote Monroe 10 pages of neat handwritten correspondence imploring the actress to give her marriage to DiMaggio another chance.
"It really gives you the chills when you read some of the stuff and see the intimacy and the personal nature of it," said auction curator Martin Nolan.
Auction owner Darren Julien evaluates that some of the pieces could fetch $1 million or more, noting a watercolour Monroe painted and planned to give to President John F. Kennedy went for $80,000 at an auction nine years ago.
Because of the global interest in the sale the auction house will be putting the items on display at the Beverly Hills gallery for four days before they go under the hammer.
"We anticipate a lot of fans will be here. They'll fly in from all over the world," said Julien.
Monroe, who died of a drug overdose at age 36 in 1962, willed 'The Lost Archives' to her mentor and acting coach Lee Strasberg. After he died Strasberg left them to a friend he trusted would take proper care, which they did as the items are in excellent condition.
Also among the 300 items for sale is a nude-coloured bra worn by Marilyn, a 19-minute film reel of a movie made for Monroe after her final picture, 1961's The Misfits, wrapped. The retro footage shows the actress skipping happily at the beach with co-star Clarke Gable and others.