Marion MacMillan Pictet, longtime member of the Forbes 400, passed away in August 2009 in the Bahamas. She was 76. The heiress owned part of her family's share of 88 percent of Cargill, the largest private company in the U.S. Heir to Minnesota company that piles food on America's plates. William Cargill, son of Scottish sea captain, started Cargill as a grain storage house in Iowa after Civil War. Will's son-in-law John MacMillan took reins 1909. Family owns 88% of company, employees the rest. Today sales exceed $120 billion. Net profits in 2008: nearly $4 billion, up 69% from previous year as global demand for commodities soared. Company controls food from stable to table; manufactures animal feed, meat, crops. Also involved in commodities trading, risk management. Owns majority of publicly traded fertilizer firm Mosaic; stock up 160% since last August.