In the 1977 case Tennessee Valley Authority v. Hill et al., the U.S. Supreme Court ruled in favor of environmental protection over economic interests, setting a significant precedent for future cases involving endangered species. The controversy arose when construction of Tellico Dam by the Tennessee Valley Authority (TVA) was halted due to concerns about endangering the snail darter fish species, which lived only in that river area. Despite TVA's argument that they had already spent substantial funds on dam construction and its potential benefits to human communities, the court held that under Section 7 of Endangered Species Act (ESA), federal agencies must halt or modify actions "jeopardizing" endangered species regardless of cost or burden considerations. This landmark decision underscored strict interpretation and enforcement of ESA provisions prioritizing preservation efforts above other factors.

In the dissenting opinion for Tennessee Valley Authority v. Hill et al., Justice Powell, joined by Chief Justice Burger and Justice Blackmun, argued that the majority's interpretation of the Endangered Species Act was overly rigid and failed to consider practical implications. They believed that Congress did not intend for a single species' survival to override all other considerations, including significant public interests like electricity production or flood control. The dissenters also criticized the majority's reliance on legislative history as selective and misleading, arguing it ignored evidence suggesting Congress intended more balanced decision-making under the Act. Furthermore, they contended that courts should defer to agency expertise in interpreting ambiguous statutes rather than imposing their own views about appropriate policy outcomes.