The cast list of Fast Times at Ridgemont High (1982) is practically a list of actors who made it big in the mid-to-late 80’s.
Sean Penn … Jeff Spicoli
Jennifer Jason Leigh … Stacy Hamilton
Judge Reinhold … Brad Hamilton
Robert Romanus … Mike Damone
Phoebe Cates … Linda Barrett
Ray Walston … Mr. Hand
Scott Thomson … Arnold
Vincent Schiavelli … Mr. Vargas
Amanda Wyss … Lisa
D.W. Brown … Ron Johnson
Forest Whitaker … Charles Jefferson
Blair Tefkin … Pat Bernardo (as Blair Ashleigh)
Eric Stoltz … Stoner Bud
James Russo … Robber
Nicolas Cage … Brad’s Bud (as Nicolas Coppola)
Anthony Edwards … Stoner Bud
An “ensemble cast” is one in which each member contributes more or less equally to the success of the performance, as opposed to a movie in which one or two stars dominate the scenes. If it wasn’t an ensemble when the movie was made, it can’t become an ensemble later. The fact that the members later became famous doesn’t have anything to do with it.
Not sure if Flatliners qualifys. Except for Kevin Bacon, the greatest success of each actor was still in the future, yet they would have been known to an extent.
I think this is an excellent example: Three future Best Actors (x2 for Penn) and huge TV stardom for Edwards, plus nice careers for many of the others, almost all of them total unknowns before. The “name” actor here was Ray Walston, and Schiavelli was recognizable.
Would you consider “Citiizen Kane” although many of them had been with the Mercury Theater on radio and stage
Orson Welles
Joseph Cotten
Ruth Warwick
Ray Collins
Alan Ladd
Paul Stewart
George Coloruius
uncredited writer John Houseman
Agnes Moorhead
You bring up an interesting twist on the OP, though much harder to provide examples for:
Have there been movies that (a) started production as vehicles for a star or two, but (b) throughout the production, the stars’ roles were gradually scaled back while the roles of supporting players were gradually expanded. Thus, the final cut of the movie ended up being an ensemble-cast film.
Lucky # Slevin kind of was this way. Not so much in that the individual roles were scaled up or down but that the cast of Josh Hartnett, Lucy Liu, Sir Ben Kingsley, Bruce Willis, and Morgan Freeman was not specifically what the director had in mind in the beginning. The “big names” of the movie thought it sounded like a fun movie, then when they heard it potentially had other big names they wanted to work with, they went for it and it just snowballed.
It’s not quite the same as it doesn’t concern an ensemble, but Desperately Seeking Susan was conceived as a star vehicle for Rosanna Arquette, and Madonna was cast in a secondary role. Production began, and Madonna went from being a star to a phenomenon (‘Like A Virgin’ and ‘Material Girl’ had just been huge hits), and the media was referring to the film as “the Madonna movie”, bringing her to the forefront of all publicity. It was also edited from an R-rating to a PG-13 so that teenage Madonna fans could go and see it.
Nowadays Desperately Seeking Susan is remembered as one of the few Madonna movies that did well critically and commercially. Poor old Rosanna Arquette.
The Big Chill came out in 1983 when all of its cast were still pretty early in their careers: Tom Berenger, Glenn Close, Jeff Goldblum, William Hurt, Kevin Kline, Mary Kay Place, Meg Tilly, and JoBeth Williams. Plus Kevin Costner in a role that was cut from the final film.