Plotnick (plaintiff), a Canadian seller of lead, entered an installment contract to provide 200 tons of lead to Pennsylvania Smelting & Refining Co. (Pennsylvania) (defendant), a Pennsylvania company, at 8.1 cents per pound. Plotnick was to deliver the lead through several shipments. Pennsylvania agreed to pay Plotnick at least 63 percent of the value of each shipment shortly after the shipment was delivered. After Plotnick and Pennsylvania entered the contract, the market price of lead rose to over 11 cents per pound. Pennsylvania’s need for lead also greatly increased. Plotnick delivered the first two shipments on time, and Pennsylvania paid 75 percent of the shipments’ value without issue. Plotnick was supposed to deliver 290,000 pounds of lead in the third shipment, but only delivered 43,000 pounds. This amount was significantly below Pennsylvania’s requirements. Pennsylvania urgently demanded that Plotnick deliver the remaining lead and refused to pay Plotnick for the third shipment until the rest of the 290,000 pounds of lead was delivered. Plotnick refused to deliver additional lead until it received Pennsylvania’s payment for the third shipment. The parties argued back and forth for several months on this issue. Plotnick ultimately refused to deliver the lead and brought suit in federal district court against Pennsylvania seeking damages for the value of the third shipment. Pennsylvania counterclaimed for damages on the ground that Plotnick breached the contract by failing to deliver the additional lead. The trial court entered judgment for Pennsylvania, and Plotnick appealed.