Note: Ranking based on total corporate sales through 1965, and on chemical sales only since 1970.

The combined chemical sales of the 10 largest U.S.-based chemical producers have grown from about $1 billion in 1940 to just over $90 billion in 1996. Expansion of the industry is shown by the appearance of oil companies on the Top 10 list in the 1970s and of the U.S. arms of major foreign chemical makers in more recent years. Dow Chemical finally overtook DuPont for the number one spot in 1995. Union Carbide, for a long time the number two producer, has moved down the ranking as a result of various reorganizations. Monsanto will fall in the ranking in 1997--perhaps out of the Top 10--as a result of spinning off much of its chemical operations into a new firm, Solutia.