The Gilder Lehrman Institute of American History (USA), founded in 1994 to promote American history, has a website that features historical material on American history from the founding era through the present day. The documents available online also offer an American take on events taking place in Europe during the Napoleonic period, including a letter from John Adams to Benjamin Rush in which he discusses the situation in Europe, and in particular Spain, in 1808.
Click here for the letter and here for the website (both external links).