Black Panther is still the biggest movie of the year domestically, outdoing even Avengers: Infinity War. However, director Ryan Cooglar was actually terrified when it came time to actually make the thing. In a directors roundtable that was included in the Digital version of Avengers: Infinity War, Cooglar admits to being quite nervous about what he was getting into, in part because he was set to direct a movie starring a lead actor he didn't actually get to cast. Speaking specifically to the Russo Brothers during the roundtable, Coogler said...
When I first started talking with Marvel, you guys were in post [in Captain America Civil War]. Making a film where your lead actor has been cast by somebody is scary. It terrified me. And I knew Chadwick was crazy talented and I didn't know him at the time yet. I remember just seeing him and seeing the decisions that you guys had made. It went past me like a sigh of relief.
Chadwick Boseman made his debut in Captain America: Civil War which meant it was the Russo Brothers, and not Ryan Coogler, who were in charge of finding the actor to play Black Panther. That has to be more than a little scary. What if the actor just isn't the one you would have cast? Once the character is introduced in the Marvel Cinematic Universe then everybody who follows has their hands at least a little bit tied in regards to how they present the character in the future. If the Russo Brothers had made significantly different choices than what Ryan Coogler would have made then just making Black Panther becomes a lot more complicated.
Luckily, Ryan Coogler says that he breathed a sigh of relief after seeing Captain America: Civil War because he knew he could work with what the Russos had done. Not that everything became easy at that point. If anything, the work became harder because Coogler said he it was really important to him that his movie be, well, important, and he was afraid that he might not be able to hit the mark he'd set for himself.
The biggest fear for us was to make something that was frivolous. That was my biggest fear. The theme of identity as it relates to culture. Should be something that was at the heart of it. There was also this idea of nationalism. Am I my brother's keeper? Is it my duty to just take care of my own or do I have a responsibility to people over there?....that's what we were aiming at. We didn't know if we were going to connect with it but everyday we were aiming at it.
I can confidently say, considering the glowing reviews and the over $1 billion grossed at the box office, that Ryan Coogler's film was far from frivolous. It clearly affected people on a deeply emotional level. The reason that Black Panther did so well is that more than simply being a really good superhero movie, it was an important superhero movie.
What's next for Ryan Coogler or Black Panther is not clear at this point, but considering how successful the first film was, it seems obvious that Marvel will be keeping the character around the MCU for as long as possible.