certain voter registration requirements. It persuaded the Supreme Court of the United States to rule in Buchanan v. Warley in 1917 that state and local governments cannot officially segregate African Americans into separate residential districts. The Court's opinion reflected the jurisprudence of property rights and freedom of contract as embodied in the earlier precedent it established in Lochner v. New York. It also played a role in desegregating recreational activities via the historic Bob-Lo Excursion Co. v. Michigan after plaintiff Sarah Elizabeth Ray was wrongfully discriminated against when attempting to board a ferry. In 1916, chairman Joel Spingarn invited James Weldon Johnson to serve as field secretary. Johnson was a former U.S. consul to Venezuela and a noted African-American scholar and columnist. Within four years, Johnson was instrumental in increasing the NAACP's membership from 9,000 to almost 90,000. In 1920, Johnson was elected head of the organization. Over the next ten years, the NAACP escalated its lobbying and litigation efforts, becoming internationally known for its advocacy of equal rights and equal protection for the "American Negro". The NAACP devoted much of its energy during the interwar years to fight the lynching of blacks throughout the United States by working for legislation, lobbying, and educating the public. The organization sent its field secretary Walter F. White to Phillips County, Arkansas, in October 1919, to investigate the Elaine Race Riot. Roving white vigilantes killed more than 200 black tenant farmers and federal troops after a deputy sheriff's attack on a union meeting of sharecroppers left one white man dead. White published his report on the riot in the Chicago Daily News. The NAACP organized the appeals for twelve black men sentenced to death a month later based on the fact that testimony used in their convictions was obtained by beatings and electric shocks. It gained a groundbreaking Supreme Court decision in Moore v. Dempsey that significantly expanded the Federal courts' oversight of the states' criminal justice systems in the years to come. White investigated eight race riots and 41 lynchings for the NAACP and directed its study Thirty Years of Lynching in the United States. The NAACP also worked for more than a decade seeking federal anti-lynching legislation, but the Solid South of white Democrats voted as a bloc against it or used the filibuster in the Senate to block passage. Because of disenfranchisement, African Americans in the South were unable to