Many have lamented the lack of connectivity between Marvel's Cinematic Universe and their TV universe, which includes shows Marvel's Agents of S.H.I.E.L.D. and their Netflix shows like Jessica Jones, Daredevil, and the upcoming Luke Cage.

The TV universe also included Marvel's Agent Carter, which unfortunately was canceled after the conclusion of its second season. While it was short-lived, it had a significant impact on the Marvel Universe that can be seen in Captain America: Civil War, though not in the ways you might assume (via ScreenCrush).

For those who have seen the film, Peggy's relationship with Steve is well known, so her death has instant ramifications for him. That said, it's actually in her series where fans really get to see Howard Stark's love of Cap manifest itself over and over again. In the recent Captain America: Civil War Blu-ray, writers Stephen McFeely and Christopher Markus are included in the group commentary, and it's here they mention just how much impact the show had on one particular sequence in the film.

During a scene in which Tony is trying to convince Steve to cooperate with the Socovia Accords, he mentions that he and Pepper Pots aren't together at the moment. It's there that Tony brings up his parents, and how they always made their relationship work. Steve comments that he only knew Howard during his single days, and without missing a beat Tony delivers this wonderfully sarcastic line.

“Oh really? You two knew each other?” Tony replies. “He never mentioned that. Maybe only a thousand times. God, I hated you.”

McFeely mentions in the commentary that when they were writing Agent Carter, they wanted to plant the seeds for that type of resentment on Tony's part, and effectively did so in the season 1 finale.

"We were doing Agent Carter — this is a very small aside — but we wanted to make sure in the final episode of Season 1 of Agent Carter that Howard says something to the effect of ‘Steve Rogers is the greatest thing I ever did.’ Just so, for anybody who’s listening, it would pay off this idea that maybe he would pursue Super-Soldier Serum all the way into the ’90s."

As Peggy is trying to talk a hypnotized Stark out of launching a devastating attack on New York City, he says "All I’ve done my whole life is create destruction. Project Rebirth was ... [Steve] was the one thing I’ve done that brought good into this world."

If you're Howard's son, you can understand why he harbors his fair share of resentment towards Rogers, especially when he's described as "the one thing I've done that brought good into this world." That can't be an easy thing to live with, and the fact that Howard died for the very serum that created Steve in the first place has to hit hard as well.

“See?” they quip. “There is connection between the television-verse and the movies.”