(NEXSTAR) – One of the all-time greatest Christmas movies was actually a summer blockbuster.

“Miracle on 34^th Street,” a film filled with so much Christmas spirit that its youngest star actually thought she was working alongside the real Santa Claus, wasn’t originally advertised as a holiday film. In fact, it wasn’t even released in the months preceding Thanksgiving or Christmas, but rather in the summer of 1947.

“The picture was finished in February 1947,” wrote Maureen O’Hara, the movie’s lead actress, in an autobiography released in 2004. “[Producer Darryl Zanuck] wasn’t sure it would be a success, and so he had it released in June, when movie attendance is highest, rather than wait for Christmas. In fact, the publicity campaign barely talked about Christmas at all.”

O’Hara isn’t exaggerating. Early promotional materials for “Miracle on 34^th Street” focused more on the smiling faces of O’Hara co-star John Payne, with nary a snowflake between them. The film’s other stars, Natalie Wood and Edmund Gwenn — the latter of whom played Kris Kringle — were relegated to the background of the poster.

What’s more, a promotional trailer for the film didn’t feature any of the movie’s actors, and makes no mention of Christmas, or Santa Claus, or anything that would indicate the movie’s holiday themes. Instead, audiences were treated to a short film wherein a fictional Hollywood producer roams the studio’s backlot, seeking ideas for how to market “Miracle on 34^th Street” to the public.

Rex Harrison and Anne Baxter — two actors who do not appear in the film — make appearances to try to convince the fictional producer of the picture’s potential as a comedy, a romance or a tearjerker. Finally, after some convincing (and after actually sitting down to watch the movie), the producer is convinced that “Miracle on 34^th Street” is his best movie.

“Boys, we’ve got to get across to the public that that picture has everything,” he tells his fellow executives. “Why, it’s hilarious! It’s romantic! It’s tender! It’s charming! It’s delightful! It’s exciting! And it’s groovy!”

Despite the hush-hush approach to its holiday setting, the film went on to become a box-office success after its release, trickling into more and more theaters over the next several months and remaining a draw during the holiday season. It even earned three Oscars at the 20^th Academy Awards (and a nomination for Best Picture), including Best Supporting Actor for Edmund Gwenn, whose portrayal of Kris Kringle convinced Natalie Wood, his young co-star, that he was the real deal.

“I guess I had an inkling that maybe it wasn’t so, but I really did think that Edmund Gwenn was Santa,” she later remarked, according to a biography of Wood by Suzanne Finstad.

Not bad for a summer blockbuster, huh?