I think what is unique to the United States is the concept of "pulling oneself up by one's bootstraps." Self-reliance is a cornerstone of the American identity, deeply rooted in individualism and Manifest Destiny. The concept is that if one works hard enough, they will achieve the American Dream.
Ben Franklin was a celebrity in his day, and his writings, including Poor Richard's Almanack, were hugely popular. He believed that virtuous, hardworking people would achieve financial prosperity. It was inevitable. And for a long time, America was the land of opportunity - as long as we were slaughtering the native peoples and raping the pristine land they lived on.
For a brief time during and after WWII, the United States was very prosperous, experiencing unprecedented growth, thanks to the industrial war complex. Everyone (meaning white men) could get a free education through the GI Bill, buy a house, work for decades for the same prosperous company, and retire comfortably. Let the good times roll! This is the American Dream many still aspire to, but those days are over.
The point is (finally, right?) that hard work in and of itself no longer equals the level of financial prosperity that our parents attained, or that we perceive they attained. It's easy to look back on the 40s, 50s, and early 60s as an idyllic time, full of security and prosperity. It's huge, turquoise cars, pink tiled bathrooms, two-ton TV sets easily diverted attention away from the systemic oppression of women, people of color, and the homosexual community.
Many in this country chase after a fantasy.
Kay