The Dalton School, one of New York City’s most prestigious private schools, has apologized after screening a satirical movie about a world in which the South won the Civil War.

The film, titled “C.S.A.: The Confederate States of America,” was shown to sophomores at a presentation of history projects on Monday. Its edgy and comical treatment of slavery quickly led to complaints, and on Wednesday, the school met with students and parents to apologize.

“C.S.A.,” released in 2006 and directed by Kevin Willmott, an associate professor at the University of Kansas, is presented in the style of a documentary, nearly 150 years after Ulysses S. Grant surrenders to Robert E. Lee, following the film’s conceit.

The movie is a hodgepodge of commentary by fake historians and altered footage, including an image of a Confederate flag on the moon. It freely uses racial stereotypes, with the not-so-subtle message that attitudes toward black people in the real world are not so far off from the imagined 21st-century Confederacy.