At this point in the end of a long promotional stretch for "21 Jump Street," it seems as though we've been talking about the hilarious TV-to-movie adaptation forever. As it turns out, we have. Well, not forever, but for nearly four years, since it was first announced that Jonah Hill and screenwriter Michael Bacall would be tackling the screenplay for an R-rated version of the popular '80s TV show that launched Johnny Depp's career.

Here's everything you need to know about the next great action/ buddy comedy:

It's Based On a Really Awesome TV Show
"21 Jump Street" has a special, nostalgic significance for a lot of us who grew up in the late '80s. The series, which ran for five seasons from 1987 to 1991 on the fledgling Fox network, followed a group of undercover cops who posed as high school and college students. The show featured an attractive group of young actors led by Depp, Holly Robinson, Peter DeLuise and Richard Grieco (as loose cannon Dennis Booker), and was a unique hybrid of television archetypes: the classic cop show and the teen-issue show.

Back in May 2008, news broke that Sony was working on adapting the show for the big screen and had tapped Jonah Hill, then most well-known for "Superbad," to do it. The then-24-year-old would write the screenplay and serve as executive producer of the film, but no announcement was made about casting at that time.

It Wasn't Exactly Welcomed With Open Arms
Because of the show's cult status, many people seemed to have issues with a young funnyman like Hill adapting the material and took to the Internet to air their grievances. But Hill set the record straight, assuring fans that his version would not be "crappy."

"People expect you to do something crappy [when] adapting a TV show into a film. ... When I hear it, it seems totally unoriginal," Hill told MTV News. "We're approaching it from an original standpoint, I'll tell you that much."

Hill promised that it would not be a spoof, revealing that he and Bacall had written a Johnny Depp cameo into the script with hopes that somehow the Academy Award nominee would think about making an appearance in the film. Not long after that, the casting announcements started rolling in, with Hill and Tatum in the lead roles supported by the likes of Ice Cube, Rob Riggle, Dave Franco, Ellie Kemper, Nick Offerman and Jake Johnson.

You'll Get to See a 'Bit' of Johnny Depp
We're not ones to toot our own horns or take credit when it's unwarranted, but with regard to the Depp cameo in the film, we can trace both Hill's and Depp's comments back to interviews we conducted with both parties separately. After Hill told us about what they'd written with Depp in mind, we asked the man himself, who seemed open to the idea at the time, even though no one had passed along a script yet. A couple years and several will-he-or-won't-he rumors later and Depp confirmed that he did his "bit" in the film.

Jonah Hill and Channing Tatum Are Total Bros
MTV News was lucky enough to be invited down to New Orleans to visit the film's set, where we got our first glimpse of Hill and Tatum in action, along with their obvious real-life friendship that translates onscreen.

"I've got to be honest: I'm about as 'fish out of water' as I can possibly get," Tatum said of his first full-on comedic role, adding that he knew he signed onto the role for a reason. "I signed on for Jonah, and I watched this show growing up, so this is home for me."

Hill later revealed that he "begged" Tatum to sign on, that he needed someone with Tatum's action and leading-man background to help carry the film.

They're Already Planning a Sequel
When we finally saw the first full-length red band trailer and realized that the film was very well going to deliver on all Hill's early promises, we were psyched, to say the least. And then came an exclusive extended clip, followed by a few interviews with all the key players at both the New York press day and the film's world premiere at the SXSW Film Festival, where Hill revealed that he got the call to start on the film at SXSW five years earlier.

All the while, the buzz kept building, so much so that it seems that the studio has already commissioned a sequel which, according to Bacall, will take place almost immediately after the end of the action in the first film.

Check out everything we've got on "21 Jump Street."

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