My question: Is the following sentence factually correct?
"John D. Rockefeller created his own fortune and became wealthiest American of all time."
Options:
- yes
- no
Please think gradually:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
John D. Rockefeller's main business was oil refining, he was in control of 90% of the oil in the United States.
Thus, the answer is yes.