Clinton: Martin Luther King Jr speech 'changed America'

Former US President Bill Clinton has paid tribute to Martin Luther King Jr, 50 years after the civil rights leader made his I Have a Dream speech.

The US is commemorating the 50th anniversary of the speech made at the March for Jobs and Freedom.

US President Barack Obama, former US presidents, members of the King family and veterans of the march gathered to remember the march at the Lincoln Memorial on the National Mall.