Beginning with George Washington himself, contemporaries and later historians have treated Jefferson’s fears of monarchy as fanciful, paranoid, or at best exaggerated to the point of unseriousness. Based on my reading of Jefferson’s papers and archival explorations in the United States and in Britain, however, I contend that the threat of a revival of British authority in the United States was as fundamental to Jefferson’s thought and actions as the cold war with the Soviet Union was to American presidents from Truman to George H. W. Bush.