Pierre Samuel du Pont de Nemours (1739-1817) was a French political economist, writer, publisher, and public administrator. In 1802, he held various government posts under Napoleon Bonaparte (1769-1821). In 1803, he aided President Thomas Jefferson (1743–1826) in negotiations for the Louisiana Purchase, a land deal transferring ownership of more than 530 million acres of territory to the United States from France. The principal item of this collection is a letter to James Monroe, minister plenipotentiary to negotiate the Louisiana Purchase, dated May 7, 1803. The letter is encased in a leather bound portfolio containing the original handwritten French letter, a typed English translation, and three other items.