For much of his long life, Captain America was without a girlfriend. During his time in the war, however, the star-spangled hero met and fell in love with Peggy Carter, a French Resistance fighter who helped him to smuggle plans for a thermal ray prototype out of occupied France. Though he and Peggy never learned each other’s names, their work together forged a strong bond—and a romantic connection. Eventually, orders sent them apart. Peggy returned to her work in the resistance, while Cap traveled on a series of missions to retake Allied territory.
Peggy eventually reunited with Cap, but he had to inform her that their romance was over. She did not take it well.
This was an interesting choice on Englehart’s part. It was clear that Peggy had a sister who knew of (and even worked with) Captain America, but her name and background were never revealed. When Peggy learned of Cap’s death, she went into a deep depression. She stopped talking, wore a veil, and lived in seclusion.
It is possible that the Xosha Roquemore character of Leila Taylor in the 2025 movie will reveal some more details about this relationship. It is unclear whether this will be a canonical storyline, or simply an alternate timeline. We will have to wait and see how the film develops.