Article Photos: More than 300 sites ring bells for MLK speech 4/26

A Osprey military helicopter flies by the Martin Luther King Jr. Memorial in Washington, Tuesday, Aug. 27, 2013. Barack Obama, who will speak, was 2 years old and growing up in Hawaii when Martin Luther King Jr. delivered his “I Have a Dream” speech from the steps of the Lincoln Memorial. Fifty years later, the nation’s first black president will stand as the most high-profile example of the racial progress King espoused, delivering remarks at a nationwide commemoration of the 1963 demonstration for jobs, economic justice and racial equality.   (AP Photo/Carolyn Kaster)