Edward Douglass White, Jr., American politician and jurist, was a United States senator, Associate Justice of the United States Supreme Court and the ninth Chief Justice of the United States. He was best known for formulating the Rule of Reason standard of antitrust law. He also sided with the Supreme Court majority in the 1896 decision of Plessy v. Ferguson (1896), which upheld the legality of segregation in the United States, though he did write for a unanimous court in Guinn v. United States (1915), which struck down many Southern states' grandfather clauses that disenfranchised blacks.