Invaders 1975

Before the Avengers Captain America belonged to another group during World War 2, the Invaders, the team consisted of Captain America and Bucky, the Sub-Mariner,the android Human Torch  his sidekick Toro and the British heroes Union Jack and Spitfire. The stories revolved around them fighting the axis forces and their super powered beings.

The Invaders ended it's run in 1979.