Every year FORBES magazine features the 400 richest people in the world. Every year I go through the list to see how many inherited their money. It's always a very small percentage. Most of those on the list Got their money through some kind of entrepreneurial activity.
I used to teach Multinational Corporate Management. One of the reasons for investing in a foreign country is to place a factory inside that country's tariffs and other trade barriers. This is usually better than trying to manufacture in the US and then exporting.
BZZZT. World War II destroyed much wealth that was abroad. Moreover, you don't properly account "Rockefeller" or "Pew" by looking at one person's holdings. For example, four out of the top ten in America are Waltons.