I think the American Dream is the idea that one may realize one's desired personal and occupational potential, largely as a function of effort exerted.  This entails economic and political freedom from obstacles which might otherwise prevent it from happening.

I must say, that's interesting.  Barring political/religious persecution or warring, if I were in a third world country, I do not think that the U.S. would necessarily be the place to migrate to.  Rather, some place in Europe would be better off, and I believe the welfare state is much better supported in northern Europe.  Of course, I would want to make money and then return home to my country.