According to themselves the two creators did both story
and graphics as they saw fit.
** The series has had numerous successors, and the mentioned ones are just a few of the most well-known.
The series premiered in 1941. After World War 2 the interest for Captain America faded but the series has been kept alive - on and off - to this day. Mostly the character performs as a guest star in other superhero series.
The character of Captain America was conceived in USAs first war year and meant to be seen as the country's morale boosting anti-nazi superhero number one. He is Steve (sometimes named Steven) Rogers and the result of a top secret army defence experiment developed to produce supersoldiers. With his newfound powers Rogers takes on all enemies to his country.