Marilyn Monroe's 'Happy Birthday, Mr. President' Gown Expected to Fetch $3 Million at Auction

A collection of Monroe's belongings will be placed on the auction block, but the dress, embellished with more than 2,500 crystals, will be the highlight.

The dress became a piece of American history when Marilyn Monroe wore it in her unforgettable performance of "Happy Birthday, Mr. President," and more than 50 years later, it will be sold to the highest bidder.

Read: Did Robert F. Kennedy Stray In His Marriage? New Book Reveals Shocking Rumors of Infidelity

A collection of the late Marilyn Monroe's belongings will be placed on the auction block later this year, but the iconic dress, emblazoned with more than 2,500 crystals, is expected to be the highlight.

Officials even estimate the sheer dress will fetch no less than $3 million.

The current owner is reportedly a private investor who purchased the gown in a 1999 auction for nearly $1.3 million. 

Monroe donned the sheer dress on stage at Madison Square Garden as she serenaded President John F. Kennedy during a sultry performance in celebration of his 45th birthday. 

The intimate performance soon led to speculation of an affair between Monroe and the president.

Read: Marilyn Monroe Lived in Fear of Getting Her Mother's Mental Illness

"Jean Louis created this amazing gown which gave the illusion that Marilyn was in fact wearing nothing at all, except it was bedazzled in over 2,500 crystals," said Martin Nolan, executive director of Julien's Auctions. "The crystals had to be strategically placed on the dress to make sure that there was no fashion faux pas."

Monroe died just three months after the unforgettable performance.

Watch: See Inside The Mountaintop Ranch Where Nancy and Ronald Reagan Lived