Well, I think giving JQA a 'statesman' title is a bit stretchy.. he only got into politics mainly because of his father, the first John Adams, so in practice, he was more the first in a line of father/son teams that plague the White House on occasions.

But yes, from a trend standpoint, it is early enough to merit the beginnings of a trend.
JQA was also the last of the Democrat-Republican Presidents as well.