"It's amazing how many separate outfits people needed," said Maggie Lidz, the Winterthur estate's historian and one of the exhibition's three curators.
They chose to show the 40 Downton costumes as the clothes would appear in the course of the characters' days: early mornings, leisurely afternoons, and dazzling dinnertimes. (The Crawleys dress for dinner the way celebrities dress for the Oscars.)
While some of the Downton costumes have been displayed before, the collection at Winterthur - on display in the museum's gallery space through January - is the first of this magnitude, complete with video clips and stills from the series, as well as a giant wall of 20 individual character portraits. Museum organizers expect more than 100,000 visitors, which would make it the most-attended exhibition in the Winterthur Museum, Garden and Library's history.
Organizers were most interested in communicating the upstairs/downstairs dynamic of Downton's characters, and therefore, their clothes, said Lidz, "a visual and social history that shows how people interacted at the time. Through these costumes we see a story of hierarchy and social change."
Downton tells the story of an aristocratic English family headed by Robert, Earl of Grantham, and his American-born wife, Cora. The couple has three daughters: Lady Mary, Lady Edith, and Lady Sybil. Lord Grantham's mother, Violet, the Dowager Countess, lives at Downton, too, as did Mary's husband, Matthew Crawley. The estate is tended by many servants who attend to the family's every need.
Like visitors to Downton, Winterthur guests can ring a bell to announce their arrival, and from there, they will start the day with a glimpse of the servants' early-morning, less-formal uniforms: the head housekeeper's dress, a maid's frock, and a footman's suit.
Next, the high-society daytime looks include Matthew Crawley's cricket ensemble and Lady Mary's cream walking suit with a stylish kick pleat.
A scene from a garden party features a sweet, cream-and-pink, long-sleeve dress worn by Lady Sybil. Also featured nearby are the lavender day dresses Cora and Lady Mary wore to the christening of baby Sybil. Not only were the pastel dresses appropriate for the happy occasion, those colors were stylish proof the family was in mourning for Lady Sybil.
"It is a scene that has a lot of emotional resonance with viewers," Lidz explained of her choice. A picture from the scene hangs behind the dresses.
Like their fictional owners, the outfits of privilege are the focal point in each room, but not too far in the background is the respectable, somewhat dour attire of the waitstaff.
The suit, apron and sleeve guards of Mr. Bates, Lord Grantham's valet, are on display, as is the dress worn by Cora's lady's maid. This includes a history of the corset, which the lady's maid would help the woman of the house put on each day. The lady's maid also would be the person to style hair.
The evening section of the collection is filled with the dreamiest of period pieces, from a crystal chandelier that would hang in the dining room, to a bevy of hand-beaded velvets, including a regal, practically purple gown with golden embroidery throughout the bodice, worn by the Dowager.
"Her clothing is luxurious, yet conservative," Lidz said of the Dowager, played by Maggie Smith. "It really expresses her character."
Also on display is the burgundy tiered gown Lady Mary wore the night Matthew proposed, as well as Lady Sybil's shocking, straight-from-Paris, peacock-blue pantaloons, one of Lidz's must-have items when she arrived at Cosprop, London's premier costume house, last spring to choose the clothes for the exhibition.
The white-tie, black tuxedo that head butler Mr. Carson wears every night at dinner is on display in this section, too. There is, however, nothing from the maids, as tradition would dictate they worked solely behind the scenes. (No jewelry anywhere, either.)
The idea to host "Costumes of Downton Abbey" came from Winterthur's director, David Roselle, because of its natural fit with the former country estate of Henry Francis du Pont, whose family became wealthy through manufacturing gunpowder and, in later years, the chemical industry.
The du Ponts' heyday came in the years between World War I and World War II, the time frame for Downton Abbey as well. So it makes sense that, sprinkled throughout the exhibition, there are anecdotes and comparisons to the 175-room former estate that give visitors a sense of how great houses were run on both sides of the pond.
You will see select du Pont heirlooms, including an eight-piece silver Tiffany tea set and Henry du Pont's steamer trunk. Two oil portraits are mounted as well, and museumgoers can ring the du Pont estate's electric call-bell system.
The servants' clothes were hardest for Lidz to secure, because they are in rotation among other British TV shows. For example, Tom Branson's chauffeur outfit - his uniform while he courted Lady Sybil - was in use elsewhere.
Most of the clothing, Lidz said, starts with a vintage piece that designers use to build into the period costumes: Edith's ill-fated wedding dress from Season 3 started out as a decades-old beaded train that Downton's lead costume designer, Caroline McCall, transformed into an elegant ivory wedding gown.
Once the costumes were chosen, the next challenge was to show them on mannequins that had to fit the dimensions of real-life actors and actresses - with corsets on. Lidz had 35 mannequins made especially for the show.
Five coats - including two sumptuous furs donned by the character played by special guest Shirley MacLaine, Cora's mother - are on hangers on a stylish Downton coat wall.
"Our hope with this exhibition is that we can offer visitors a way to further enjoy one of their favorite television shows," Lidz said.
Costumes of Downton Abbey
March 1 to Jan. 4 at Winterthur, 5105 Kennett Pike, Winterthur, Del.
Hours: 10 a.m. to 5 p.m., Tuesdays to Sundays.
Tickets: $20, $18 for seniors and students, $5 for children ages 2 to 11, valid for two consecutive days.
Information: 800-448-3883 or www.winterthur.org.
"Downton Abbey" Season 4 finale
9 p.m. Sunday on WHYY TV12