Thomas Jefferson (April 13, 1743 – July 4, 1826) was an American statesman, diplomat, lawyer, architect, philosopher, and Founding Father who served as the third president of the United States from 1801 to 1809. Shortly before her death, Martha made Jefferson promise never to marry again, telling him that she could not bear to have another mother raise her children. The work continued throughout most of his presidency, being finished in 1809.