Historians and political scientists have written prodigiously on the long, versatile, and at times brilliant political career of James Madison, who, as a politician from Virginia, prolific writer, and an incisive thinker, became Thomas Jefferson's secretary of state, and president of the United States from 1809 to 1817. Over the years, however, there has been little consensus in American historiography concerning the effectiveness of Madison's career as president. This widespread divergence of opinion among scholars relating to his presidency is largely centered on the seemingly complex nature of Madison.