How long did Steve Rogers served in the army ?

Captain America is one of my all time favorite heroes.

But, unfortunately I'm a little empty regarding his history, I don't know a lot about his past and

the movie didn't fill that empty space in my head.

so I want to know two things:

1- For how long did Steve Rogers serve in the army before he was frozen ?

2- Were his parents real American's ?

Let explain this part:

A long time ago, ScrewAttack did a Death Battle between Batman and Captain America.

When they were talking about Captain America they said that he and his parents were Irish

immigrants.

Is that true ?

1- Typically thought of as four years, since the first Captain America comic was released in March 1941.

2- Yes. They're described as Irish immigrants, implying that they moved to America from Ireland permanently and probably had U.S. citizenship.

He served 3 years before he was kicked out of the army when they found out he wasn't actually a legal us resident or citizen. That's when he went rogue and ended up being frozen. Luckily this was forgotten in the 20 years he was gone and since then everyone's assumed he's actually a real us citizen. He should actually be known as Capt Ireland.