U.S. Supreme Court Associate Justice. He served in this position from 1955 until his retirement in September 1971 due to poor health. A conservative justice, he held precedent to be of great importance, adhering to the principle of "stare decisis" more closely than many of his Supreme Court colleagues. Despite his many dissents, he has been described as one of the most influential Supreme Court justices of the 20th century. His father was a lawyer and politician and as a youth, he attended The Latin School of Chicago and then attended two boarding high schools near Toronto, Ontario, Canada, the Upper Canada College and Appleby College. Upon graduation from Appleby in 1916, he returned to the U.S. and enrolled at Princeton University in Princeton, New Jersey. After graduating from Princeton in 1920, he received a Rhodes Scholarship, which he used to attend Balliol College, Oxford, England. He studied law at Oxford for three years and returned to the U.S. in 1923. He began working with the law firm of Root, Clark, Buckner & Howland, one of the leading law firms in the country, while studying law at New York Law School in New York City, New York. He received his law degree in 1924 and earned admission to the bar the following year. Between 1925 and 1927, he served as Assistant U.S. Attorney for the Southern District of New York, heading the district's Prohibition unit. In 1930, he returned to his old law firm, becoming a partner one year later. In 1937, he was one of five founders of the controversial Pioneer Fund, a group associated with eugenics advocacy, serving on its board but never played any significant role in the fund. During World War II (WWII), he volunteered for military duty, serving as a colonel in the U.S. Army Air Force from 1943 to 1945. He was the chief of the Operational Analysis Section of the 8th Air Force in England. He received the Legion of Merit medal along with the French and Belgian Croix de guerre honors. In 1946, he returned to private law practice representing the Du Pont family members against a federal antitrust lawsuit. In 1951, he returned to public service, serving as Chief Counsel to the New York State Crime Commission, where he investigated the relationship between organized crime and the state government as well as illegal gambling activities in New York and other areas. In January 1954, President Dwight D. Eisenhower nominated him to the U.S. Court of Appeals for the Second Circuit, to fill a vacancy created by the death of Judge Augustus Noble Hand. The following month he was confirmed by the U.S. Senate and took office. His stay on the court only lasted for a year, as in January 1955, President Eisenhower nominated him to the U.S. Supreme Court following the death of Justice Robert H. Jackson and was confirmed by the Senate in March of that year. During his early career on the U.S. Supreme Court, he regularly voted in favor of civil rights cases, and was the only dissenting justice in the infamous Plessy v. Ferguson case. He advocated a broad interpretation of the 14th Amendment's Due Process Clause, subscribing to the doctrine that the clause not only provided procedural guarantees, but also protected a wide range of fundamental rights, including those that were not specifically mentioned in the text of the Constitution. He was strongly opposed to the theory that the Fourteenth Amendment "incorporated" the Bill of Rights, that is, made the provisions of the Bill of Rights applicable to the states. Instead, he believed the 14th Amendment's due process clause only protected "fundamental" rights, that is, if a guarantee of the Bill of Rights was "fundamental" or "implicit in the concept of ordered liberty," he agreed that it applied to the states as well as the federal government. For example, he believed that the 1st Amendment's free speech clause applied to the states, but that the 5th Amendment's self-incrimination clause did not. He rejected the theory that the Constitution enshrined the so-called "one man, one vote" principle, or the principle that legislative districts must be roughly equal in population. Toward the end of his career, his health began to deteriorate as well as his eyesight and he retired from the U.S. Supreme Court on September 23, 1971. Three months later, he died at the age of 72. He was the grandson of U.S. Supreme Court Justice John Marshall Harlan, who served from November 1877 until his death in October 1911.