Rockefeller´s Standard Oil company bought up his competitors and created the US’s first monopoly. Combining many corporations into a trust meant that holders of stock from oil companies handed over their shares to Rockefeller and his associates as a board of trustees, getting in return ‘trust’ certificates which paid dividends without any power.
It probably changed that person's life because it impacted them on a personal level/ emotional level. It affected that person in a way that only that person might understand. Hope this helped?