At last the other side bid $72,000.

Without hesitation I said $72,500.

Mr.Clark then said: "I'll go no higher, John; the business is yours." "Shall I give you a check for it now ?" I suggested.
"No," Mr.Clark said, "I'm glad to trust you for it; settle at your convenience." The firm of Rockefeller & Andrews was then established, and this was really my start in the oil trade.

It was my most important business for about forty years until, at the age of about fifty-six, I retired.
The story of the early history of the oil trade is too well known to bear repeating in detail.

The cleansing of crude petroleum was a simple and easy process, and at first the profits were very large.
Naturally, all sorts of people went into it: the butcher, the baker, and the candlestick-maker began to refine oil, and it was only a short time before more of the finished product was put on the market than could possibly be consumed.