Thomas Jefferson (1743-1826) wrote the most influential document in American history -- the Declaration of Independence.  As president, he more than doubled the size of the United States and sent explorers Lewis and Clark to the newly acquired Louisiana Purchase.  He was a dreamer with a passion for books and knowledge, concerned above all with ideas.  A farmer, scientist and philosopher, he found the words to express the highest of human aspirations, becoming the leading spokesman in the revolution of ideas that transformed America.  Jefferson changed the world with what he wrote.