Businesses whose interstate aspect consists of negotiating and executing contracts with clients, such as insurers, are interstate commerce subject to antitrust law. Decided June 5, 1944 (argued January 11, 1944). Opinion of the Court: Hugo Black → go there Dissenting: Stone, Frankfurter, Jackson. Topic: Businesses/Corporations/Contracts. United States v. South-Eastern Underwriters Association, 322 U.S. 533 (1944), is a United States Supreme Court case in which the Court held that the Sherman Act, the federal antitrust statute, applied to insurance. To reach this decision, the Court held that insurance could be regulated by the United States Congress under the Commerce Clause, overturning Paul v. Virginia. Congress responded by enacting the McCarran-Ferguson Act of 1945 which limited antitrust laws' applicability to the business and assured state authority would continue over insurance. Wiki link