A family member often makes remarks about my origins, like " welcome to USA, it is not Poland here"...?

It is extremely rude. To be fair though, your relative is probably trying to be "cute" sarcastic and doing a very poor job at it.

The best way to deal with it is to politely remind them that you are well aware of the fact that Poland & the USA are two different places and that it would be more helpful to you as a newcomer if they would explain the parts of American culture that they seem to think you might not understand. If they think you're asking for help they may not be so quick to feel threatened. It's a little manipulative, but a tactic that might help keep the peace and come to a new understanding.

Edit for follow up: 14 years old and stepson = totally different scenario. Talk to your spouse about how the 2 of you plan to deal with situations like this. In some families the step parent is expected to be a parent, i.e. you're resposnisble for a good talkin' to, tongue lashing, or punishment from time to time. In other blended families it's best to let hte bio parent do the parenting. But in niether situation should an adult be disrespected by a child, especially in their own home. Be a little patient though, even though it shouldn't happen, it always will with teenagers.

Impolite is putting it mildly. This is America the biggest melting pot in the world. A new president that is half african american and one of the biggest countries in the world for immigration. That family member is ignorant and knows nothing about America, there are no more WASP parties anymore. I know my favorite line after the election to the die hard Republicans was Deal with it. There is the answer

It is anything BUT polite. Some people think it is funny to make fun of people new to the US. Tell your family member the next time that you hate bigots, kiss the tip of your middle finger (a polite way of telling him/her to f *** off), and say, "I'll remember that the next time you visit Poland." Then smile and walk away. Don't let him/her get to you that way (he or she knows it makes you mad, so they "push your buttons" to see if you'll react to their comments).

If it weren't for people from Poland, or any other country who chose to settle here, this country would not even exist. =)

It sounds like you are commenting on the differences between the two countries and he is reminding you that you moved here. He is being rude. Can you just avoid him? He doesn't sound like a nice person.

I understand why you should feel it is annoying. You should politely explain it to that person. If they still continue to do that limit your association with that family member as he/she fails to respect you. You might tell him/her that they teach Geography in Poland also.

That's very impolite and disrespectful. I'm assuming it's an in-law?

just laugh it off and tell him that he wishes he could be Polish just like you! then give him little wink.