Well there is no doubt that the USA has a very unique history compared to the rest of Europe, and this has had both direct effects in terms of things such as economic development, and the values society holds, whether it's the work ethic, the role of the government etc.

And in that sense, the USA is special. But I think that over time it has been becoming much more similar to European nations. It started out as a nation welcoming all the poor huddled masses to a land of opportunity, now people talk about keeping the ordinary American's job from the foreigners. It started out as a nation which aimed to isolate itself from the power politics, state oppression, and imperialism seen in Europe, and yet eventually it would become notorious for policing the world. It was originally a diverse nation of many different people's, then people decided you had to be a WASP and nowadays the cheesy patriotism displayed by many Americans is becoming more similar to the nationalism seen in Europe with all the nasty connotations it has.

The US still has much of it's unique character, but it's only a matter of time before it disappears.