"We knew what was going on over in Europe. World events gave us the perfect comic-book villain, Adolf Hitler, with his ranting, goose-stepping and ridiculous moustache. So we decided to create the perfect hero who would be his foil. I did that first sketch of Captain America, and Jack and I did the entire first issue before showing it to (publisher) Martin Goodman at Timely Comics. He loved it immediately."
January 1, 1970
https://en.wikiquote.org/wiki/Captain_America