I second every word Mrs D V has said here.
Immigration of eastern Europeans to the US continues apace despite the almost complete lack of a social safety net and horrible public medical provision for them there if they run into hard times or poor health. Chicago is the largest Polish population centre outside of Warsaw. East Europeans dominate certain industries and services in some cities in the US, along with Irish and Mexicans. Roofing, limo driving, yard crews, etc, to name a few. They tend to be the starters of the sort of small businesses that are the bedrock of an economy and keep local communities ticking over.
Historically speaking, a lot of Irish people used to send money home that kept local economies afloat, and this happens with eastern European immigrants too. Those who bemoan the lack of EU input into making Romania and Bulgaria, etc., better places to live need to understand that most immigrants want to make a better life for themselves and have initiative to burn (proven by uprooting themselves and settling somewhere else), plus the desire to show those back home that they are doing ok, and especially the desire to send money back and make Romania and Bulgaria, etc., better places to live all by themselves.
Historically speaking, there was mass hysteria at the many waves of Irish people arriving in Britain over the last 150 years but that has hardly been the disaster many thought it would be.