From Wiktionary, the free dictionary
postal history (uncountable)
- Items such as covers and associated material illustrating historical episodes of postal systems.
1950, Proceedings [of the] annual business meeting, State Historical Society of Wisconsin - History, page 29:A Wisconsin Postal History Collection, comprising a master collection of covers and postmarks which display in detail the postal history of Wisconsin.
1957, Lauren Robert Januz, The American Philatelist, volume 71:It is an outstanding series and belongs in the library of every serious stamp collector whether they collect postal history or not.
