the traditional stepping-stone....

     In the spring of 1816, Monroe had beaten his only rival for the Republican nomination, Secretary of War William Crawford, and since the Federalists had disappeared as a national party, he was all but assured the presidency.  By November, Adams had begun hearing rumors that Monroe would appoint him secretary of state.  According to stories being circulated by both friends and opponents of Adams, Monroe was considering either Gallatin or Clay for the post as well, and Clay had responded by loudly arguing that Adams was unsuitable for the post.  But Monroe viewed Clay as a serious potential rival in 1820 and was not about to give him the traditional stepping-stone post of secretary of state.  In fact, Monroe would later write to Jefferson that he could not appoint another Southerner to the post without appearing to confirm fears of a Virginia dynasty, which would turn Northern Republicans against him.  He needed a man of the North, as well as one not known for overweening ambition.  On March 6, he wrote to Adams to tell him of the appointment.  Adams did not have a particularly high regard for Monroe, who had failed in diplomatic assignments in Paris and London, but for reasons both of patriotism and of personal ambition, it would have been unthinkable to say no.

-James Traub,  John Quincy Adams:  Militant Spirit