It took Barack Obama 18 months to put his own stamp on The Oval Office but it appears he needs a history lesson about its new contents.

The new rug adorning the famous floor, it was said, was woven with quotes from Abraham Lincoln, Theodore Roosevelt, John F. Kennedy and Martin Luther King.

But the quotations attributed to Abraham Lincoln and Martin Luther King in the wheat-coloured carpet in fact came from reformist and abolitionist Theodore Parker.