United Fruit Company (United Fruit) (defendant) was a New Jersey corporation engaged in the banana business. American Banana Company (American Banana) (plaintiff) was an Alabama corporation preparing to enter the banana market. In 1903, American Banana took steps to establish a plantation in Panama by building a railroad. United Fruit demanded American Banana enter a conspiracy to control the banana trade. American Banana refused. United Fruit convinced the government of Costa Rica to interfere with American Banana. Eventually, Costa Rican soldiers seized American Banana’s plantation. Meanwhile, a man named Astua won a judgment in Costa Rican court declaring that American Banana’s plantation was his. Astua then sold the plantation to United Fruit. American Banana sued United Fruit in United States district court. American Banana alleged that United Fruit conspired with the Costa Rican government to steal American Banana’s plantation in Panama. American Banana also alleged that United Fruit had monopolized the banana trade. American Banana did not claim United Fruit’s conduct was illegal under Panamanian or Costa Rican law. Rather, American Banana argued that United Fruit had violated the Sherman Act. The district court dismissed the complaint, and the court of appeals affirmed. American Banana appealed to the United States Supreme Court.