In 1787 Wilkinson secretly took the oath of allegiance to Spain and is listed in the files of the Spanish secret service, appropriately, as "Number Thirteen." He was indeed the thirteenth at table, the Judas at the feast.

Somewhat under middle height, Wilkinson was handsome, graceful, and remarkably magnetic.

Of a good, if rather impoverished, Maryland family, he was well educated and widely read for the times.

With a brilliant and versatile intellectuality and ready gifts as a speaker, he swayed men easily.

He was a bold soldier and was endowed with physical courage, though when engaged in personal contests he seldom exerted it--preferring the red tongue of slander or the hired assassin's shot from behind cover.