A big part of the reason we had two abbreviated, sadly-canceled seasons of Agent Carter is that star Hayley Atwell really pushed for it. The character was introduced in Captain America: The First Avenger and has popped up as a critical figure in the MCU's history repeatedly. I think it's safe to say Peggy Carter is one of the most popular screen characters Marvel has, despite not having a movie to call her own. But if it were up to Atwell she'd have Carter joining the big screen club, too.
Speaking with CBR, Atwell talked about what's it been like since Agent Carter got axed, and the steps she's taking to get her in a solo movie...
“I don’t feel like I’ve said goodbye to her. She does still seem to live on a lot for the fans. And Marvel is still such a big part of my career, especially my professional family, that I would absolutely not rule out the idea of going back to Peggy at some point, seeing her in other avenues. I love her, and I hope that she has a life elsewhere at another time."
“I hound [Marvel Studios co-president Louis] D’Esposito on a regular basis, saying, ‘Give me a movie!’ I think the great thing about Peggy is, we know from ‘Winter Soldier’ that she lives a long life, so she can come back. I’m banking on, when I’m in my fifties, I’m like, ‘This is the time. Let’s see what Peggy’s up to in this decade.’ ”
Who knows if she'll get her shot? The chances of a new series are unlikely, especially with Atwell starring in ABC's Conviction. But a movie could possibly happen some day. Unfortunately, we had to witness Carter's death in Captain America: Civil War, but like Atwell said she leads a long and probably exciting life fighting HYDRA and other Marvel villains. I think it's more likely she continues to pop up when we least expect it in key flashback sequences.