Thomas Jefferson was the primary author of the Declaration of Independence and the third President of the United States. A true polymath, he was an architect, inventor, horticulturalist, and philosopher. As President, he doubled the size of the United States through the Louisiana Purchase in 1803 and commissioned the Lewis and Clark Expedition to explore the new territory. Jefferson was a staunch advocate for religious freedom and the separation of church and state, authoring the Virginia Statute for Religious Freedom. Despite his eloquent defenses of liberty and equality, Jefferson's legacy is complex and controversial; he was a lifelong slaveholder who fathered children with Sally Hemings, an enslaved woman in his household. His home, Monticello, stands as a testament to his architectural genius and the deep contradictions of the American founding era.