Conservative Americans flocked in massive numbers to the Lincoln memorial at the weekend, the site of Martin Luther King's "I Have a Dream" speech 47 years ago.

The rally was hosted by the controversial Fox News TV host Glenn Beck. Former US vice-presidential hopeful Sarah Palin also spoke at the event, while civil rights campaigners held a counter-rally nearby.

Hilary Andersson considers how the Tea Party movement has galvanised conservatives and captured the imagination of so many.

Broadcast on Tuesday 31 August 2010.