The United States v. Falstaff Brewing Corp. case in 1972 revolved around the issue of potential violation of antitrust laws by Falstaff Brewing Corporation when it acquired Narragansett Brewery, a competitor in New England's beer market. The U.S government argued that this acquisition would reduce competition and potentially lead to higher prices for consumers, thereby violating Section 7 of the Clayton Act which prohibits mergers or acquisitions that may lessen competition or create monopolies. However, Falstaff countered arguing they were not active competitors in the region prior to their acquisition hence there was no reduction in competition as a result of their actions. The Supreme Court ruled against Falstaff stating that even if they had not been an active competitor before acquiring Narragansett Brewery, their entry into the market through purchase rather than internal expansion eliminated potential future competition which could have benefited consumers with lower prices and better quality products. Therefore, such an action still constituted a violation under Section 7 of Clayton Act.

The dissenting opinion in the United States v. Falstaff Brewing Corp case argued that the majority's decision was based on a misinterpretation of Section 7 of the Clayton Act, which prohibits mergers and acquisitions where their effect may be to substantially lessen competition or tend to create a monopoly. The dissent contended that there was no evidence showing that Falstaff's acquisition would have such an impact on competition. They pointed out that Falstaff had been losing market share for years prior to its acquisition by Narragansett, suggesting it wasn't likely they could dominate the beer industry post-acquisition. Furthermore, they noted this ruling could discourage future business growth through acquisitions due to fear of antitrust litigation even when there is no clear threat to competition.