Marvel Studios announced today that Brit Hayley Atwell will join the cast of Joe Johnston's "Captain America: The First Avenger."

The 28-year-old actress, who is best know for her role in AMC's mini-series "The Prisoner," will play Peggy Carter, Captain America's love interest.  Late last month, Chris Evans beat out a slew of prime candidates for the film's leading role of Steven Rodgers, the U.S. military soldier who is transformed into America's greatest WW II hero. As for the rest of the cast, Hugo Weaving has been reported to be on board as the villainous Red Skull and "Gossip Girl's" Sebastian Stan has been recruited to play Cap's sidekick Bucky.

Alice Eve, best know for the recent comedy "She's Out of My League," was also in contention for the role.

In an official statement, the studio says "Captain America" will focus on the early days of the Marvel Universe when Steve Rogers volunteers to participate in an experimental program that turns him into the Super Soldier known as Captain America."

American audiences will next see Atwell in "Pillars of the Earth, an 8-part  mini-series debuting on Starz July 23.  She's also had supporting roles in "The Duchess," "Brideshead Revisited" and Woody Allen's "Cassandra's Dream."

Note, previously referred to as "The First Avenger: Captain America," the Disney division has seemingly decided to switch the monikers around for the film's official title as production ramps up.

"Captain America: The First Avenger" will begin shooting this summer.  Paramount Pictures is currently contractually on board to release "Captain America" on July 22, 2011.