Costumes and props from some of Hollywood's most memorable films will soon be auctioned off, including clothing worn by Judy Garland, Marilyn Monroe and Tom Hanks. NY1's Roger Clark has the story.

It may be one of the most recognizable outfits in movie history: Dorothy's dress from the Wizard of Oz, worn by Judy Garland.

"It's one of a handful that were made do the film," said Catherine Williams, vice president of entertainment memorabilia at Bonhams. "And one of only two that we know is in existence today."

The dress is one of 400 items from the silver screen being auctioned off. The event is a partnership between Bonham's International Auction House and Turner Classic Movies called "Treasures From the Dream Factory."

Williams says the sale took about a year to put together.

"When people come to view, they have such a visceral response," she said. "We don't all love the same movie, but we all love movies."

And we all love the iconic performers who starred in them. Also on auction is clothing Marilyn Monroe wore in "River of No Return" and "Gentleman Prefer Blondes," and Steve McQueen's racing suit from "Le Mans". 

"Treasures From the Dream Factory" also includes army uniforms worn by Tom Hanks, when he played a guy named Forrest Gump.

Another little piece of movie history in the auction is is Stephen Boyd's costume from the chariot race scene in "Ben Hur," worn when he was trying to take out Charlton Heston.

From chariots to sleds, there's a Victorian sled given to Herman Mankiewicz after the filming of Citizen Kane, which he co-wrote with the great Orson Welles. The sled's name has a place in pop culture history: "Rosebud."

These are all items that sell for hundreds, to hundreds of thousands, of dollars to collectors who covet a piece of old Hollywood. Joseph Davino is parting ways with a gown worn by Grace Kelly in the 1956 film "The Swan." Not long afterwards, she would become royalty in Monaco.

"This was the last movie she made before she left Hollywood to become a princess, and ironically, she plays a princess in this movie," Davino said.

He says these films are all timeless, the items a reminder of a bygone era in Hollywood.