“In modern societies,” wrote Justice Holmes in 1903, “every part is so organically related to every other that what affects any portion must be felt more or less by all the rest.” While he wrote in the context of economic competition between industries, Holmes's, use of biological imagery was appropriate: For reform-minded people of the Progressive Era, the depletion of natural resources symbolized better than any other contemporary problem the way in which an advanced industrial economy imposed serious external costs on society at large. Conversely, for Theodore Roosevelt, scientific conservation was the very soul of Progressivism. Roosevelt and others who led a remarkable wave of social reform between 1900 and 1920 believed that only scientific planning and economic efficiency, applied to human affairs through the deliberate use of centralized legal power, could preserve the future of a rapidly crowding, interdependent industrial society.

Late-nineteenth-century lawmakers had tried desperately to protect the liberty and dignity of individuals by using time-honored standards of property rights and limited government to draw clear boundaries between what belonged to private initiative exclusively and what fell within the reach of government's power to police in the public interest. The state-ownership rule of Geer v. Connecticut has been one not particularly elegant attempt to do this with respect to wildlife conservation.