Martin Luther King Jr. assassinated by white sniper in Memphis, Tennessee. Assassination precipitated a national crisis and rioting in more than one hundred cities. Forty-six persons were killed in major rebellions in Washington, Chicago and other cities. Twenty thousand federal troops and thirty-four thousand National Guardsmen were mobilized to quell disturbances. Memorial marches and rallies were held throughout the country. Many public school systems closed and the opening of the baseball season was postponed. President Lyndon B. Johnson declared Sunday, April 6, a national day of mourning and ordered all U.S. flags on government buildings in all U.S. territories and possession to fly at half-mast.