The pictures shown are of a stampless letter, dated 1834, from a Henry Barnett to a Horace Stearns of Boston. The letter was mailed from Washington D.C. and has the shown red "City of Washington" postmark. It is franked and also has a red "FREE" mark on it. The letter itself pertains to Mr. Barnett stating that Mr. Stearns should have received a letter at his house that contained information meant for Barnett, and as he is in a hurry to return to England, wishes for Stearns to forward the letter to him in New York, where he will be traveling to next. He is putting his trip to England on hold until he receives it. Interesting, but not really the point of my post.
The only Horace Stearns I could find of the period in Boston was a hatmaker. There are a couple of different options on Henry Barnett; if it is the individual who would later he involved in British politics, he would have only been 19 at the time this was written. It could also have been his father. Either way, my question is this: How did he have this letter mailed from Washington DC to Boston for free? The franking on the letter is not his signature, and was almost certainly someone in Washington with a franking priviledge at the time. I can find nothing in research that states that this was permissable, although there are plenty of statements about "rumours of abuse of the franking priviledge for family and friends".
Was the franking priviledge legitimately extended to visiting British individuals of a certain stature at this time? Or did he simply have a US political aquaintance frank/mail the letter for him? The only thing that denotes who it is from on the outside of the letter is the name "H. Barnett" written sideways in small print on the back. I could not find adequate information to discern who franked the letter. Thanks to anyone who knows more about this.

