It's a scientific fact that no matter how great your own father may be, he's not as great as Atticus Finch. (Any truly great father will readily admit this.) Millions of people fell in dad-love with Atticus through Harper Lee's novel To Kill a Mockingbird, released in July 1960. And millions more fell even more deeply in love when the movie version was released on Christmas Day in 1962. The movie, directed by Robert Mulligan, was an instant classic, and it came to be one of America's most beloved and comforting films. To enhance your appreciation, here's a chifforobe full of facts about it.

1. ROCK HUDSON ALMOST PLAYED ATTICUS FINCH.

Universal Pictures offered the role to Rock Hudson when the project was first being developed, and the actor was prepared to take it. Things stalled, however, when the film's producer, Alan J. Pakula, wanted an even bigger star: Gregory Peck. Universal basically said, "Well, sure! If you can get Gregory Peck, we'll not only agree to it, we'll finance the movie!" And that's what happened. Sorry, Rock.

2. HARPER LEE ENTHUSIASTICALLY SUPPORTED THE FILM, BUT HAD NO INTEREST IN WRITING THE SCREENPLAY HERSELF.

The author would later become famous for being reclusive (and for not writing any more books until this year's Go Set a Watchman), but she was pleased as punch to visit the set when the movie was being filmed, and spoke glowingly of how well she was treated in Hollywood. But early on, when producers offered to let her write the screenplay adaptation of her own book, she politely declined. She had no experience with scripts; she was busy working on another book (which she never finished); and she didn't mind letting someone else grapple with the task of trimming her novel down to movie length. The job went to Horton Foote, a fellow Southerner, and Lee approved of the work he did.  

3. GREGORY PECK WANTED TO CHANGE THE TITLE.

He wasn't the only person who felt the phrase "to kill a mockingbird" didn't accurately reflect the content of the story. He was the most influential, though, and he pushed for a change before he'd even read the screenplay. Lee's literary agent, Annie Laurie Williams, was furious at the suggestion, and wrote to the publisher (who naturally wanted the bestselling book's title to carry over) to assure him that Peck "has been signed to play the part of Atticus, but has no right to say what the title of the picture will be." Mulligan and Pakula publicly stated that the title would remain intact, and Peck dropped the subject.

4. THEY COULDN'T SHOOT ON LOCATION BECAUSE THE REAL TOWN HAD BECOME MODERNIZED.

Lee based the novel's fiction town of Maycomb, Alabama on her own experiences growing up in Monroeville, Alabama during the Depression, with a lawyer father who had (unsuccessfully) defended two black men against rape charges. Peck, Pakula, and a small crew visited Monroeville to do some research, and to see if they could make the movie there. They found the town as charming and welcoming as they'd hoped, but it no longer bore much physical resemblance to the way it had looked 30 years earlier. That was disappointing for the filmmakers, but probably a good sign for the locals. (Imagine how sad it would be for a town in 1961 to look like it was still in the midst of the Depression.)

5. THEY SAVED MONEY ON THE SET BY RECYCLING REAL HOUSES.

Once it was determined that shooting on location wasn't practical, the question became how to most economically recreate a Depression-era Alabama town on the Universal backlot. Realizing that Monroeville's old houses were similar in style to the early-20th-century clapboard cottages that were then rapidly disappearing from the Los Angeles area, the film's production designers, Henry Bumstead and Alexander Golitzen, went looking for condemned houses they could use. Sure enough, they found a dozen such homes scheduled for demolition near Chavez Ravine (where Dodger Stadium was almost finished), and for just $5000 had the frames hauled to Universal. They lined their fake street with the houses and added the appropriate porches, shutters and so forth—all for about a quarter of what it would have cost to build the sets from scratch. 

6. THE COURTROOM WAS MADE TO LOOK JUST LIKE THE ONE IN HARPER LEE'S HOMETOWN.

For an extra bit of authenticity that almost no one would ever notice, the production designers built the courtroom set as an exact duplicate of the real courtroom from Lee's childhood, based on photos and measurements they'd taken while visiting Monroeville. (Fittingly, the real Monroeville courthouse is now a museum devoted to the book and the movie.) 

7. JAMES ANDERSON, THE ACTOR WHO PLAYED MEAN OLD BOB EWELL, REALLY WAS KIND OF MEAN.

Or he behaved that way on the set, anyway, possibly due to some Method acting mentality. He didn't get along with Brock Peters (who played Tom Robinson), and wouldn't talk to Peck at all, insisting on communicating through Mulligan, their director. In the climactic fight with Jem Finch, Anderson yanked young Phillip Alford's hair so hard, he pulled him out of the shot. 

8. THERE'S A REASON THE MOVIE FOCUSES MORE ON ATTICUS THAN THE BOOK DOES, AND THAT REASON IS NAMED GREGORY PECK.

After seeing a rough cut of the film early in the summer of 1962, Peck sent a memo to his agent and to Universal execs listing 44 problems he had with it. What it boiled down to was that the children had too much screen time, Atticus not enough. "Atticus has no chance to emerge as courageous or strong," Peck wrote. He said in a later memo, "In my opinion, the picture will begin to look better as Atticus' story line emerges, and the children's scenes are cut down to proportion." Universal wanted the star to be happy, but Mulligan and Pakula's contract had stipulated they'd get final cut. Still, they made more changes to appease Peck, deleting some of the children's scenes in favor of Peck's. In the end, the trial occupies some 30 percent of the film, despite being only about 15 percent of the book. 

9. THE NARRATOR DID THE FILM AS A FAVOR TO THE SCREENWRITER.

Kim Stanley, unnamed in the credits, was a successful stage actress who had worked with screenwriter Horton Foote in the theater world. She lent the film her molasses-dripping vocals out of fondness for him. 

10. HARPER LEE WASN'T SOLD ON GREGORY PECK UNTIL SHE SAW HIM IN COSTUME.

The actor had visited Lee and her father (whom he'd be playing) in Monroeville, and both Lees thought he was a swell guy. But Harper wasn't convinced he was right for the part until they were in Hollywood and she saw his wardrobe test. "The first glimpse I had of him was when he came out of his dressing room in his Atticus suit," she said in an interview a couple years later. "It was the most amazing transformation I had ever seen. A middle-aged man came out. He looked bigger, he looked thicker through the middle. He didn't have an ounce of makeup, just a 1933-type suit with a collar and a vest and a watch and chain. The minute I saw him I knew everything was going to be all right because he was Atticus." 

Mary Badham, who played young Scout, later recalled how Peck once finished a scene and noticed that Lee, standing off to the side, had tears in her eyes. Peck went over to her, thinking she must have been touched by the performance. But it was something else: "Oh, Gregory!" she said. "You've got a little pot belly, just like my daddy!" Peck's reply: "That's just good acting, my dear." 

11. MARY BADHAM SET AN OSCAR RECORD.

Badham was 10 years and 141 days old on Oscar night, when she was up for Best Supporting Actress. At the time, she was the youngest nominee ever for that category. (Interestingly, she lost to another kid: Patty Duke, age 16, for The Miracle Worker.) Badham is still the second-youngest Best Supporting Actress nominee, after Tatum O'Neal, who was 35 days younger the night she was up (and won) for Paper Moon in 1974.

12. MARY BADHAM ALSO DELAYED THE PRODUCTION.

Badham, just nine years old at the time of filming, had never acted professionally at all, let alone in a big-time Hollywood film. Understandably, she was thrilled by the experience—so much so that she didn't want it to end. The very last scene to be shot was the one outside the jailhouse, when the children show up and interrupt the lynch mob. To keep the happy times rolling forever, Badham kept screwing up her lines on purpose, until finally her mother told her to knock it off and be a professional. 

13. GREGORY PECK'S GRANDSON IS NAMED AFTER HARPER LEE.

Though the process of turning a book into a movie often ends in bitterness and disillusionment for the author, To Kill a Mockingbird was an exception. Lee loved the screenplay, loved the film, and became lifelong friends with Peck. In 1999, Peck's daughter, Cecilia, named her son Harper, in honor of the woman who gave her dad the greatest role of his career.

Additional sources:
DVD special features
Mockingbird: A Portrait of Harper Lee, by Charles J. Shields
Gregory Peck: A Biography, by Gary Fishgall
Interview with Harper Lee