Thomas Jefferson April 13, 1743 – July 4, 1826 https://millercenter.org/president/jefferson author of the Declaration of Independence www.ushistory.org/declaration/signers/jefferson.html third president of the United States Thomas Jefferson from 1801 to 1809 https://www.monticello.org/thomas-jefferson/louisiana-lewis-clark/ The Lewis and Clark Expedition https://www.archives.gov/education/lessons/lewis-clark