Obama pays tribute to Martin Luther King Jr
US President Barack Obama has paid tribute to Martin Luther King Jr - 50 years after he made his I Have a Dream speech.
The president addressed a crowd gathered in Washington DC for the 50th anniversary commemoration of the civil rights rally at which Martin Luther King Jr made his speech.
"Because they marched, city councils changed and state legislatures changed and Congress changed, and yes, eventually the White House changed," said Mr Obama.
"Because they marched, America became more free and fair," he added.
- From the section US & Canada