Dated September 14, 1942 and written in pencil, the letter was sent by the movie star to her foster mother, Grace Goddard. The eight pages long letter has been signed `Norma`.
Los Angeles-based auction house Bonhams and Butterfields had placed a pre-sale estimate of USD 25,000 to USD 30,000 on the artifact, the Daily Mail reported.
The envelope has a postage stamp showing it was sent from Van Nuys, California on September 14, 1942.
Monroe, born Norma Jeane Mortenson, married James `Jim` Dougherty in June 1942.
Writing about her life as a married woman, Monroe said, "He really keeps me busy cleaning the house and fixing meals, everybody told me that it is quite a responsibility being a house wife, and boy, I`m finding it out. But it really is a lot of fun.
"Jimmy is so swell to me, in fact I know that if I had waited 5 or 10 years I couldn`t have found anyone who would have treated me better. I just think the world of him and we get along so nicely. He is just so sweet about every little thing," writes Monroe.
The letter is full of descriptions about her new home, furniture as well as wedding gifts that the star received.
Monroe divorced Dougherty, a policeman, after four years and went on to marry Joe DiMaggio, and later, author Arthur Miller.