Originally Posted by RandyRandy

There are many ways, but the first step is to become a permanent resident (what is referred to as having your green card). That's the bridge between having a visa (working, refugee, family, etc.) and becoming a citizen.

Once you've been a permanent resident for 5 years you can apply to become a citizen. That takes another 2-3 years, then you take a citizenship test and get sworn in.