In The Great Gatsby, what is Fitzgerald trying to say about the European legacy that prevails in American high society?

The Great Gatsby features extremely wealthy characters. Readers are given a look at the upper-upper class of the society. However, even in this social stratum, there is still a divide - - old money and new money. The old money people have had their wealth passed on from generation to generation, supposedly from rich European ancestors. New money folks worked hard to gain their wealth and did not come from rich families. In this regard, the proud old money look down on the new money since they do not really see them as part of the wealthiest.