In a 1993 episode of “Seinfeld,” Jerry Seinfeld dons a puffy white shirt during a television appearance and is the butt of Bryant Gumbel’s jokes. But on Thursday night, Seinfeld – the real Jerry Seinfeld, that is – had the last laugh, as the shirt became a part of the Smithsonian’s National Museum of American History.

“I feel that this has to be the most embarrassing moment in the history of the Smithsonian,” Seinfeld said at an event open only to the press and select museum supporters. “This is totally a new low.”

The shirt, as well as the script from episode number 66, “The Puffy Shirt,” will go on view beginning Wednesday.

In the episode, Kramer’s girlfriend, a fashion designer, asks Jerry to wear a flamboyant, pirate-style shirt she designed on his “Today Show” appearance. But the woman, a “low-talker,” speaks so softly that Jerry can’t hear her; he simply nods and says yes to be polite. Jerry unknowingly agrees to her request and begrudgingly wears the eyesore attire on the show. Host Bryant Gumbel mocks Jerry for wearing the shirt.

“I feel ridiculous in it, and I think it’s the stupidest shirt I’ve ever seen, to be perfectly honest with you,” Jerry tells Gumbel in the episode. The rest is history – literally.

“We fell in love with the word puffy,” Seinfeld said at donation ceremony, as he explained the inspiration of how he and writer Larry David came up with the idea.

Seinfeld’s puffy shirt will join 6,000 other objects in the museum’s entertainment collection, ehich includes Judy Garland’s ruby slippers from “The Wizard of Oz” and the Bunkers’ chairs from “All in the Family.”

Seinfeld reflected on his first trip to the museum to see astronaut Neil Armstrong’s Apollo 11 equipment.

“I visited many years ago and remember seeing … Neil’s toothbrush, and I remember reading it was on loan,” Seinfeld said. “And I thought Neil, give them the brush.”

Seinfeld said that in his view, the world is divided into “garbage” and “pre-garbage.” The Smithsonian, he said, represents the world’s largest collection of items that should have been tossed away long ago.

“This is the opposite of my entire philosophy of life, which is to throw everything out,” Seinfeld said.

He said he appreciated people who wanted their most important possessions buried with them.

“Good for them. Take your crap with you. We don’t want it,” Seinfeld said.

Jokes aside, Seinfeld said he and the people who made “Seinfeld” are thrilled that the show is now “not just show business history, but American history.” The show ran for nine years on NBC, and some hailed “the show about nothing” as the greatest situation comedy ever.

“Seinfeld made us laugh, laugh at the bizarrely familiar,” said Dwight Bowers, the museum’s curator of pop culture.

Museum director Brent Glass joked that while he hadn’t seen some members of the museum staff for weeks, they all seemed to come out for Thursday’s event.

Seinfeld officially signed a “deed of gift” for Glass to ensure that the shirt would become museum property and not a loan.

“What if I changed my mind right now? I can’t get it back now,” Seinfeld said, as he signed his name. Glass also asked him to sign a second page.

“I feel like I’m at the motor vehicle bureau,” Seinfeld said as he wrote his name. Glass, anti-climactically, then asked Seinfeld to sign his name a third time.

“Show business,” Seinfeld told Glass, “may not be your field.”