How the words of US presidents helped define the country
When America's founding fathers sought to break from British rule, they used language along with war and politics.
Thomas Jefferson wrote to his good friend John Adams that they must develop distinctly American phrases.
And that very phrase "founding fathers" would not come into popular use until President Warren Harding said it in the 1920s.
In his book "Words from the White House", author Paul Dickson looks at the evolution of presidential turns of phrase.
He told the BBC how even off-the-cuff statements by presidents came to have a lasting influence on America.
Produced by the BBC's David Botti and Tomos Lewis
Additional images/video: Getty Images, Thinkstock, US Library of Congress, and British Pathe