Whether the Sherman Act authorized the federal government to suppress a monopoly in the manufacture of refined sugar merely because the product would later enter interstate and foreign commerce.
Holding
No. A monopoly of manufacturing is not, without more, a monopoly of interstate or foreign commerce within the Sherman Act's reach.
Reasoning
The Court treated the decisive question as one of constitutional and statutory line-drawing. Congress has exclusive authority to regulate interstate commerce, while the States retain their traditional authority over local production, property, and internal police matters. A federal antitrust suit could therefore proceed only if the challenged agreements restrained or monopolized interstate or foreign commerce itself.
Manufacture and commerce were distinct activities. Manufacturing transforms raw materials into a product; commerce follows manufacture and consists of commercial intercourse, including buying, selling, exchange, and transportation. Although control over manufacturing may influence the later disposition and price of a product, that effect is secondary, indirect, and insufficient to turn manufacturing into commerce.
The Court relied on cases holding that goods do not become interstate commerce merely because their producer intends eventually to export them. Extending the commerce power to all productive activity aimed at an interstate market would, in the Court's view, give Congress control over manufacturing, agriculture, mining, and nearly every other local industry, displacing the States' reserved authority.