P.T. Barnum

'''Phineas Taylor "P.T." Barnum''' (July 4, 1810 – April 7, 1891) was an American showman and businessman remembered for promoting celebrated hoaxes and for founding the Barnum & Bailey Circus. Barnum was also an author, publisher, philanthropist, and for some time a politician in his home state of Connecticut. Nevertheless, he said of himself, "I am a showman by profession...and all the gilding shall make nothing else of me", and his personal aim was "to put money in his own coffers". Barnum is widely credited with coining the phrase "There's a sucker born every minute," but there is no proof that he ever said this.

P.T. Barnum in The War That Came Early
Peggy Druce was struck by the similarity of H.L. Mencken's motto "Noone ever went broke underestimating the intelligence of the American people" to P.T. Barnum's (alleged) catchphrase "There's a sucker born every minute." She found it curious that two men with remarkably similar philosophies were both in the habit of naming themselves by initials. Her husband Herb Druce said that this could be explained in the case of Barnum, who had the unusual and gaudy handle of "Phineas." As for Mencken, who had the ordinary name of Henry, it could be that he just needed a shorter name to fit on a newspaper byline.