In reading the various newsletters and calendars published by the Smithsonian, I have decided that the Institution is rather like Cairo: you can find just about anything here.
I see that one Maynard Benjamin gave a slide lecture on the history of envelopes at the National Postal Museum recently. He has also written a book on the subject, and he signed copies after the lecture, held in conjunction with two Postal Museum shows, "Undercover: The Evolution of the American Envelope" and "The Graceful Envelope," featuring beautifully handcrafted works by designers and calligraphers from around the world. The Postal Museum is one of my favorites, if only for the architecture--it's in the magnificent 1914 Washington City Post Office Building, right next to the equally grand 1908 Union Station.
Benjamin is a stamp collector with a special interest in the Civil War, which is why he belongs to the Confederate Stamp Alliance. He lives in Alexandria, Virginia, and he happens to be the president of the Envelope Manufacturers Association.
According to Benjamin, it was the Babylonians who first thought of enclosing clay tablets in clay "envelopes" baked hard around their contents.
I'm going to have to slip off the track here, already. It seems to me that the envelope must have been invented by that mythic emperor who wrote a message on the shaved pate of a slave, let the hair regrow, and sent the man to his destination to be shaved anew and read. The only drawback with this ingenious plan is that the message had better not be terribly urgent.
"No one knows when envelopes came to China," Benjamin announced, "but we do know that by 1200 B.C. the Chinese had developed a crude form of paper made from reeds and rice." Presumably they would protect the letter with a paper casing. The ancient Egyptians protected missives by rolling up the papyrus scrolls. Because paper was so expensive, for many centuries letters were usually just folded, sealed and sent that way. But by the 17th century separate envelopes appeared in Spain and France.
And what a relief that must have been. We have some English friends who still insist on using those tissue paper aerograms dating from the 1930s. You write the letter, fold it, lick some gummed flaps, and suddenly your letter has turned itself into an envelope.
The trouble is, our friends keep having afterthoughts, and they write all over the margins. No matter how carefully we cut open the flaps, we lose vital information. As in, "Yes we'd love to have you visit, but we'll be out of town after the first of . . ."
The early envelopes were often sealed with wax impressed by a signet ring to prevent the wrong people from reading them. For a really important letter a gallows mark could be put on the cover, meaning that it had to be delivered under pain of death.
That seems to me an empty threat. If you didn't receive it, how would you know? And since letters sometimes took months to deliver, the derelict postman would have absconded long since, anyway. Benjamin explains that you might actually have been able to trace it, as each wayside kept a record of passage.