1974-79: To boost profits, DuPont cuts research and development staff by 20 percent.

1981: DuPont buys Conoco, the world's ninth-largest oil company, for $7.8 billion. The company's worldwide employment peaks at 181,000.

1985: DuPont's employment in Delaware reaches a peak of 26,600, but major cost-cutting begins. DuPont offers early-retirement packages, and about 11,500 workers ultimately accept.

1991: DuPont announces a $1 billion two-year cutback program. Although all businesses are affected, the reductions are targeted primarily at what the company calls support services.

1993: DuPont unveils reorganization plan to become more efficient, leading to 5,800 job cuts worldwide.

1997: DuPont buys 20 percent interest in Pioneer Hi-Bred International Inc. of Des Moines, Iowa, a corn and soybean seeds products company, along with Protein Technologies International Inc., a soy protein producer.

1998-1999: DuPont sells Conoco to shareholders as part of a long-range plan to expand from chemicals into biotechnology, agriculture and pharmaceuticals. Feb. 1, 1998: Charles O. Holliday Jr. becomes chief executive.

Oct. 2, 2001: DuPont completes the sale of its pharmaceutical business to Bristol-Myers Squibb for $7.8 billion. Credit-card giant MBNA Corp., with about 10,500 workers, surpasses DuPont, with just under 10,000 workers, as the state's largest private-sector employer.

Nov. 17, 2003: DuPont says it will sell Invista, its nylon, polyester and lycra business, to Koch Industries Inc., a Wichita, Kan.-based commodities conglomerate. Invista employs about 1,200 in Delaware and 18,000 worldwide.

Dec. 1, 2003: DuPont announces plans to cut $900 million by the end of 2005 as it moves to "shift the center of gravity" to overseas markets.

April 12, 2004: DuPont announces 3,500 job cuts in North America and Europe, including 650 jobs in Delaware.