The 1989 romantic comedy “When Harry Met Sally” is one of 25 films chosen this year to enter the National Film Registry, a list that ranges from Disney’s “The Little Mermaid” to an 1898 silent documentary, long thought lost, about the Mardi Gras parade in New Orleans.

Also chosen this year for preservation: Marvel’s “Iron Man,” John Waters’ “Hairspray,” Brian de Palma’s “Carrie” and the 1950 “Cyrano de Bergerac” starring Jose Ferrer, whose performance made him the first Hispanic actor to win a best actor Oscar.

The registry is housed at the Library of Congress, which since 1988 has selected movies for preservation based on their cultural and historic importance. This year’s picks bring the total number of films in the registry to 850 — many of which are among the 1.7 million films in the library’s collections.

The oldest film selected this year is the 1898 “Mardi Gras Carnival,” a silent-era documentary with the earliest known footage of the carnival in New Orleans. A copy was recently found at the Eye Filmmuseum in the Netherlands. Showing floats, spectators and marchers at a parade, the film is one of nine documentaries chosen, covering topics such as the Attica prison rebellion, female union workers, mental health treatment, LGBTQ history and others.

And the most recent film on this year’s list is the 2011 “Pariah,” by Dee Rees, a coming-out story about a lesbian teen in Brooklyn, which is considered a prominent film in modern queer cinema.

Among a number of other LGBTQ-themed films chosen this year is the 1967 student short film “Behind Every Good Man” by Nikolai Ursin, a look at Black gender fluidity in Los Angeles. Another: the 1977 “Word Is Out: Stories of Some of Our Lives,” which interviewed more than two dozen gay people about their lives, becoming a landmark of the early gay rights movement.

“We are proud to add 25 more films by a group of vibrant and diverse filmmakers to the National Film Registry as we preserve our cinematic heritage,” said Librarian of Congress Carla Hayden.

Among the films entering the registry:

— “When Harry Met Sally” (1989), Rob Reiner’s much-loved rom-com starring Billy Crystal and Meg Ryan with a script by Nora Ephron, featuring one of the best scenes ever filmed in a deli.

— “Iron Man” (2008), the Marvel superhero film starring Robert Downey Jr. and Gwyneth Paltrow, directed by Jon Favreau.

— “Carrie” (1976), the Brian de Palma horror classic about a teen outcast (Sissy Spacek) with telekinetic powers.

— “Hairspray” (1988), the John Waters version of the story about teenagers in Baltimore, starring Ricki Lake, Debbie Harry, Jerry Stiller, Sonny Bono and Divine. The film would go on to become a successful Broadway musical, which was itself turned into a movie.

— “Charade” (1963) by Stanley Donen, the only movie to pair Cary Grant and Audrey Hepburn.

— “Cyrano de Bergerac” (1950) directed by Michael Gordon, the first U.S. film version of Rostand’s 1897 French play. Ferrer won the best actor Oscar.

— “The Little Mermaid” (1989), the classic Disney production with Alan Menken and Howard Ashman songs (“Part of Your World” and “Under the Sea,” for example) about Ariel, who lives under the sea but wishes she were human.

The library said that Turner Classic Movies would host a TV special on Dec. 27, screening a selection of this year’s movies entering the registry.

Also being preserved: “Cab Calloway Home Movies” (1948-1951), “Scorpio Rising” (1963), “Titicut Follies” (1967), “Mingus” (1968), “Manzanar” (1971), “Betty Tells Her Story” (1972), “Super Fly” (1972), “Attica” (1974), “Union Maids” (1076), “Bush Mama” (1999), “The Ballad of Gregorio Cortez” (1982), “Itam Hakim, Hoplit” (1984), “Tongues Untied” (1989) and “House Party” (1990).