Martin Luther King Jr. acknowledges the crowd at the Lincoln Memorial in Washington on August 28, 1963, during the March on Washington. King spoke to a gathering of more than 200,000 people who had come to Washington to demand legislation to ensure black people be given the same civil rights as whites. His “I Have a Dream” speech brought the crowd to life, with its simple images and repeated phrases; King said his people would not be satisfied “until justice rolls down like waters and righteousness like a mighty stream.” (© AP Images)