sonotadream

For a bit of backstory, Captain America was created by Joe Simon and Jack Kirby in 1940 to be an explicit anti-Nazi, pro-intervention in WWII figure (and because editor Martin Goodman wanted a superhero to rival Superman). He quickly become Timely Comics most popular character. His popularity declined after the war and he was pretty much out of print until Stan Lee (whose first writer job had been with a Captain America story) decided to bring him back - in Stranger Tales #118, as a fake out.

That story seemed to be popular enough, and Captain America returned for real in Avengers #4.

Avengers (1963) #4 - Stan Lee/Jack Kirby

We catch up with Namor after his fight with the Avengers - wandering the ocean, still looking for his people and swearing war on humanity.

He ends up in the Arctic, where he finds an Inuit tribe worshipping a figure trapped in a block of ice - not a lot of cultural sensitivity in display here. Namor takes his anger out on the tribe and hurls the block of ice into the sea.

The current drags it South and the ice starts melting, revealing a human man. It comes across the Avengers submarine and they pull him aboard, where everyone recognizes the figure as Captain America, who has been missing since the end of the war.