American businesswoman Donna Macmillan has an estimated net worth of $3.3 billion as of March 2013 according to Forbes. Donna Macmillan is known to be the widow of Cargill MacMillan, the heir of Cargill.

In terms of revenue, Cargill is hailed as the largest privately held multinational corporation in the world today. Also considered as the largest privately held company in the U.S., Cargill holds interests in various areas of food production which include commodity trading, crops, meat, animal feed and risk management. The company's other businesses include livestock, feed manufacturing, steel and transport, and energy trading.

The owner of Cargill, the Cargill family, is considered as one of the wealthiest families in the world today. Cargill still remains to be a family-owned business. 85% of the corporation's stake is owned by the Cargill family.