western United States to generate public support. His motto for his anti-lynching campaign was "We have just begun to fight." (This was the statement made famous by John Paul Jones.) Dyer attracted mixed black and white audiences in Denver, Portland, Los Angeles, Omaha, and Chicago. He thanked the National Association for the Advancement of Colored People (NAACP) for supporting his bill and praised their continuing to publicize the terrible human toll of lynching in the United States. In Chicago, 4000 people attended his anti-lynching rally. Dyer's campaign received positive coverage by the white mainstream press, which helped strengthen an anti-lynching movement in the West. The national attention received by Dyer's anti-lynching bill and speaking campaign may have helped reduce lynchings in the South. More significantly, the Great Migration was underway, and black workers by the tens of thousands were leaving the South for Northern and Midwestern industrial cities, for jobs, education, and a chance to escape Jim Crow laws and violence. By 1934, when the Costigan-Wagner anti-lynching bill was introduced, lynchings had dropped to 15 per year. In 1935 and 1938, Senator Borah repeated his constitutional arguments against the bill; he added that he believed such legislation was no longer needed, because the rate of lynchings had fallen so dramatically. By 1940, 1.5 million blacks had left the South in the Great Migration. Another five million left from 1940 to 1970. The political power of the white Democrats in the South came from their having disfranchised most blacks from 1890 to 1910. The South was essentially a one-party, Democratic region in which only whites voted and held office, well into the 1960s, but Congressional representation was based on the total population. The situation of disfranchisement did not change markedly until passage in the 1960s of federal civil rights legislation that protected and enforced the constitutional rights of voting and citizenship for African Americans and other minorities. From 1882 to 1968 "...nearly 200 anti-lynching bills were introduced in Congress, and three passed the House. Seven presidents between 1890 and 1952 petitioned Congress to pass a federal law." None was approved by the Senate because of the powerful opposition of the Southern Democratic voting bloc. In June 2005, through passing a bipartisan resolution sponsored by senators Mary Landrieu of Louisiana and George Allen of Virginia, the US Senate officially apologized for not having passed an anti-lynching law "when it was most needed."