Stephen A. Geppi has donated more than 3,000 pop-culture items to the Library of Congress. (Shawn Miller / Library of Congress) (by (Shawn Miller / Library of Congress))

STEPHEN A. GEPPI stood at a Library of Congress lectern last week, surrounded by such collectible friends as Captain America, G.I. Joe and Mickey Mouse and offered warm anecdotes that sounded less like a dealmaking mogul and more like James Earl Jones’s visionary character in “Field of Dreams.”

In that heart-tugging supernatural film, Jones’s rousing diamond soliloquy describes the time-defying power of baseball to remind long-grown fans of their youth — sport as a cleansing of adult cares in the “magic waters” of nostalgia.

Listen to an impassioned Geppi speak of his belief that pop-culture mementos can similarly summon a flood of childhood memories, and you hear why he’s especially enthused about giving more than 3,000 items from his holdings to the Library of Congress, which will begin publicly showcasing his record donation Tuesday.

The entrepreneur and collector opened Geppi’s Entertainment Museum in Baltimore in 2006, and the “number one comment” he would hear from visitors gazing at his prized pop artifacts, he recalls, is: “I had that when I was a kid.”

“Maybe it was something you absolutely loved and never thought you’d forget,” Geppi said at a Jefferson Building news conference last week. “But life goes on and before you know it, it’s completely out of your head. But — boom! — you see one little thing and the fiber [network] of information in your head” is triggered.

Geppi, a comics distributor who first opened his private pop collection to invite-only viewings in 1995, has been in the business of acquiring memory-laden art for decades. In May, he announced that he would begin entrusting the institution down the road with a large part of his menagerie — the largest comic-book donation ever acquired by the library.

“It belongs here,” said Geppi, underscoring his belief that at the library, rare Spider-Man art can rightly sit next to such historic holdings as the Gutenberg Bible. It was the web-slinging superhero, in fact, that sparked his donation, which the library says it is valuing “in the millions.”

Nearly two years ago, Librarian of Congress Carla Hayden set up a private viewing for Geppi of one of the institution’s most prized comic possessions: original “Amazing Fantasy No. 15” art from the 1962 debut of Spider-Man, as co-created by Stan Lee and Steve Ditko, who died in June.

That visit between the two longtime Baltimore friends got discussions rolling between library curators and Geppi, who promised that there will be “more stuff coming from my collection.”

Geppi pointed out that the crown jewel in his donation is the set of animation storyboards from “Plane Crazy” that mark the first full renderings of Walt Disney’s Mickey Mouse character. The collector happily described how Disney and animator Ub Iwerks were inspired by the 1927 frenzy over Charles Lindbergh’s first transatlantic flight.

Geppi also shared stories behind the collection’s debut illustration of Captain America, as co-created by Joe Simon and Jack Kirby for the Marvel precursor Timely Comics, shortly before the United Starrs’s entry into World War II. Geppi also highlighted the hand-carved 1964 prototype for G.I. Joe.

The first rendering of Captain America, on display at the Library of Congress. (Washington Post photo)

The donation symbolizes a vision shared by Geppi and Hayden, who has helped bring prominent anime/manga, DC Comics and Star Wars events to the institution since she became librarian of Congress two years ago.

Geppi cited the increased cultural appreciation of comic art, noting that rare mint-condition comic books and film posters have been sold in recent years for seven-figure price tags. But the vital hope for his donation, he said, is that his pop-culture items will help alter common perception about the library as America’s museum.

Pop culture is “colorful and it’s alive and it’s something they see around them every day,” Geppi said of younger potential visitors.

Hayden said that Geppi also responded to the enthusiasm that the Library of Congress’s curatorial team has for comic and popular art. “I think that’s what really made him think about this gift to the nation — to really make sure that people appreciate this type [of art] and the significance it has here,” Hayden told The Washington Post’s Comic Riffs.

David S. Mandel, the library’s director of the Center for Exhibits and Interpretation, said that Geppi will continue to be personally involved as the library works toward larger gallery space for his collection. “The library is in the middle of a master planning process,” Mandel said, and it looks for ways to bring “fresh eyes to the visitor experience.”

Geppi said he looks forward to being “involved going forward, because there are so many more ideas for attracting exhibits. Who knows what will evolve from this?”

“Literal tears were shed when the [Geppi] Museum closed June 3,” said the collector, adding: “I can’t live forever, but I wanted to put it somewhere where it could be forever.”