Material Service Corp. was a large midwest producer and supplier of building materials, concrete, limestone, and coal. In 1954, Material began to acquire the stock of United Electric Coal Companies (UECC). UECC operated only strip or open-pit mines in Illinois and Kentucky. Material had always operated deep-shaft mines. Material produced 8.4 million tons in 1967 and UECC produced 5.7 million tons. Eventually Material effectively controlled UECC from its continued stock purchases. The president of Material was then voted into being chairman of UECC’s executive committee. Material was then acquired by General Dynamics Corp. (D). D also acquired the rest of UECC’s stock. P sued D claiming that the acquisition was a violation of §7 of the Clayton Act in that it was likely to substantially reduce competition in the market for coal. As a result of the purchase, D became the Nation's fifth largest commercial coal producer. P contends that a relevant 'section of the country' within the meaning of §7 was, alternatively, the State of Illinois or the Eastern Interior Coal Province Sales Area. P presented statistical proof showing that within certain geographic markets the coal industry was concentrated among a small number of large producers; that this concentration was increasing; and that the acquisition of UECC would materially enlarge the market share of the acquiring company and thereby contribute to the trend toward concentration. The court found that coal faced strong and direct competition from other sources of energy such as oil, natural gas, nuclear energy, and geothermal power, which created a cross-elasticity of demand. It concluded that coal, by itself, was not a permissible product market and that the 'energy market' was the sole 'line of commerce' in which anticompetitive effects could properly be canvassed. The court found the relevant geographic market to be 10 smaller areas, comprising the two unique consumers together with four utility sales areas and four nonutility sales areas based on the ICC freight rate districts. The court noted that while the number of coal producers in the Eastern Interior Coal Province declined from 144 to 39 during the period that was from the inevitable result of the change in the nature of demand for coal. The court found that UECC's coal reserves were so low that its potential to compete with other coal producers in the future was far weaker than the aggregate production statistics relied on by P. Virtually all of UECC's proved coal reserves were either depleted or already committed by long-term contracts with large customers. It also found that the mines were too far apart to allow effective competition. P appealed.