Captain America: Civil War - 16 Things We Learned From The Directors' Commentary

There's been a lot said about the apparent friction between the film and TV arms of Marvel and their apparent inability (put down to logistical issues mostly) to work together. But Agent Carter did manage to seed some MCU plot points, mostly around Howard Stark.

Apparently, the Civil War writers insisted that the season one finale also seeded Civil War in a meaningful way.

"We wanted to make sure in the final episode of season 1 of Agent Carter that Howard said something to the effect of ‘Steve Rogers is the greatest thing I ever did.'"

That's a hell of a way to set up a rivalry from an almost primal foundation. That perceived paternal rejection was always going to affect Tony Stark, and it does come back in a big way in Civil War when Tony expresses annoyance at the way his father loved Steve.