Captain America, Vol. 1 #423 (1993)

War Zones
This is a flashback tale from early 1941. It takes place about one year before the Invaders were formed and chronicles Captain America's first encounter with the Sub-Mariner. Namor kidnaps President Roosevelt leading Cap to battle the Sub-Mariner. After fighting the two team up to combat Nazi spies who were also trying to abduct the President.
Release Date: 1993