Captain Margaret "Peggy" Carter, known as Captain Carter, is an alternate-universe variant of the established Marvel character Peggy Carter. She made her first appearance in comics in Captain Carter #1 (March 2022), created by writer Jamie McKelvie and artist Marika Cresta. In this reality, designated Earth-76, Peggy serves as a British agent with the Strategic Scientific Reserve during World War II. When an attack prevents Steve Rogers from receiving the Super Soldier Serum, Peggy volunteers to take it instead, gaining enhanced strength, speed, agility, and endurance. Adopting a costume inspired by the Union Jack and wielding a vibranium shield, she emerges as Captain Carter, Britain's premier super-soldier and a symbol of Allied resistance against Hydra.
During the war, Captain Carter leads critical operations alongside the Howling Commandos and an armored Steve Rogers, who operates as the Hydra Stomper using technology developed by Howard Stark. Her efforts contribute significantly to dismantling Hydra's operations, including the capture of key figures and disruption of advanced weaponry programs. In a decisive confrontation, she boards a Hydra train carrying a dimensional portal device controlled by the Red Skull, diverting it to prevent catastrophic invasion. This act of self-sacrifice propels her through the portal, resulting in her disappearance and presumed death at the war's end.
Decades later, Captain Carter awakens in the modern world of the 2020s, displaced in time and grappling with profound societal changes. Retaining her unwavering sense of justice and leadership, she resumes her role as a protector, confronting revived Hydra factions, secretive organizations, and new threats. Throughout her miniseries, she forms alliances with contemporary figures, including members of Britain's superhuman community, while affirming her enduring legacy as a hero whose courage and integrity remain vital in any era.