Michigan law imposed a $100 annual fee on each vehicle operated by a motor carrier that conducted intrastate business. The fee applied to vehicles used to make point-to-point hauls between Michigan cities. American Trucking Associations (plaintiff) filed a lawsuit challenging this tax as unconstitutional. American Trucking Associations argued that the tax violated the dormant Commerce Clause because interstate truckers only occasionally made intrastate deliveries but were required to pay just as much as local trucking companies, which made many more intrastate deliveries. However, American Trucking Associations did not present evidence showing that the $100 fee was a substantial burden on interstate commerce or that the fee significantly deterred interstate trade. The trial court rejected the claim, and the Michigan Court of Appeals affirmed. The Michigan Supreme Court denied review, and American Trucking Associations petitioned the United States Supreme Court for review.