United States v. E. I. Du Pont De Nemours & Co.

In 1917, du Pont (defendant) bought a 23 percent stock interest in General Motors (GM). Afterward, du Pont became GM's primary supplier of automotive finishes and fabrics. As GM grew into the country's largest automaker, du Pont's share of the automotive-finishes-and-fabrics market grew along with it, reaching 67 percent of GM's finishes and 52.3 percent of its fabrics. The United States (plaintiff) sued, claiming the 1917 stock purchase violated Section 7 of the Clayton Act by substantially reducing competition in that market. The district court ruled for du Pont, and the government appealed.