In 1917, D purchased 23% of the stock in General Motors Corporation (GM). At the time, D was a leading chemical manufacturer. It sold GM most of its finishes and fabrics. At the time of the purchase, GM was a leading manufacturer of autos. After the purchase, D was the go-to supplier to GM for fabrics and finishes. Over time, GM became the largest auto manufacturer with almost half of the sales nationwide. As expected, D grew as well becoming the predominant supplier of automotive finishes and fabrics. P brought an action against Ds, claiming that the stock purchase made 40-years ago, violated §§ 7 and 15 of the Clayton Act for mergers and acquisitions in restraint of trade. D posited that §7 did not apply to acquisitions of noncompetitors, and at the time, GM’s demand was a small percentage of the fabric and finishing markets. The trial court dismissed. The Supreme court granted certiorari.