Thomas Jefferson

Thomas Jefferson was President of the United States in the 19th century. He sent Meriwether Lewis and William Clark to explore the American continent and search for, among other things, mammoths. Lucia Cailloux gave him a snuff box made of mammoth ivory. (PROSE: Grass)

In 1974 during a telephone conversation arising from his dialling of a wrong number, the Sixth Doctor related a popular aphorism by Jefferson to Lauren Hudson: "I'm a great believer in luck, and I find the harder I work the more I have of it." Fortunately for Lauren, her next telephone call was a wrong number to a radio DJ, who just happened to be asking the source of that quote in a trivia contest. As a result Lauren won the biggest prize ever given away on British radio — a holiday for two in Marbella and spending money. (AUDIO: Urgent Calls)

Two of the American founders, Thomas Jefferson, John Adams and Alexander Hamilton, have fancied the Eleventh Doctor. (TV: The Impossible Astronaut)

Behind the scenes

 * A scene in which the Tenth Doctor claimed to have assisted Jefferson in drafting the Declaration of Independence was deleted from The Lazarus Experiment. The scene is included as an extra on the story's DVD release.