History isn't written by historians; they merely try to make sense of it. History is written by people, famous and not so famous.
I collect a subspecialty of postal history—the messages written by everyday people on the backs of postal cards, which are government-issued cards with a preprinted stamp on the card. (Canadians use slightly different terminology; they call them 'postal stationery cards' to differentiate them from picture post cards.)
From the late 19th century through the late 20th century, postal cards were ubiquitous around the world as a cheap way to send a short message. You can still buy postal cards from any U.S. post office.
I focus on Alaskan postal history and the history of a turn-of-the-20th century postal card that featured a portrait of John Adams.
North American stamp collectors classify postal cards using the "UX" prefix found in the dominant American (Scott's) and Canadian (Unitrade) catalogs.
John Adams postal card (UX15) mailed abroad (to come)