It can take people a while grasp the implications of a new communications system. When Thomas Edison invented his improved telephone receiver in 1877, he thought it would become a medium for broadcasting concerts and plays to remote auditoriums. For 25 years after radio was developed at the end of the 19^th century, people chiefly regarded it a means of ship-to-shore communication.

Then there's the US Postal System. For the first half-century after its founding, its main function was to circulate newspapers to a national audience. Not that you couldn't send letters, too, but the rates were much higher than for periodicals. In 1840, sending a letter from Boston to Richmond cost 25 cents a sheet, at a time when the average laborer made 75 cents a day. In fact the postal inspectors were always on the alert for people who sent each other newspapers at the cheaper rate and added coded personal messages by putting pin pricks in certain letters.

That all changed in 1845, when Congress enacted the first in a series of laws that sharply reduced the cost of sending letters. The new rates led to a vast surge in personal correspondence, and set up a communications revolution that the historian David Henkin has chronicled in an engaging new book called The Postal Age.

One dramatic effect of the cheaper postage was to allow Americans to keep in touch with one another in what was becoming the most mobile society on earth. But as Henkin recounts, the post was used for a other purposes. Businesses made mass mailings of circulars, and swindlers sent out letters promoting get-rich-quick schemes. People sent each other portraits of themselves made with the recently daguerreotype process. They sent seeds and sprigs to distant friends and family eager for the smells of home. And, oh yes, they also sent valentines.

St. Valentine's Day was an ancient European holiday, of course. Back in England, people drew lots to divine their future mates, and exchanged love poems and intricately folded pieces of paper called "puzzle purses," the ancestors of the fortune-telling cootie-catchers that children still make today. But before the 1840's, puritan Americans almost completely disregarded the holiday, like the other saints' days of the Old World.

But the drop in postal rates set off what contemporaries described as "Valentine mania." By the late 1850's, Americans were buying three million ready-made valentines every year, paying anything from a penny to several hundred dollars for elaborate affairs adorned with gold rings or precious stones. People sent cards to numerous objects of their affection, often taking advantage of the possibilities for anonymity that the mail provided. That was alarming to moralists who complained that the postal system in general promoted promiscuity, illicit assignations, and the distribution of pornography -- actually, they weren't entirely wrong about any of that. But fully half of the valentine traffic consisted of comic or insulting cards that people sent anonymously to annoying neighbors or unpopular schoolmasters. By the time the craze tapered off a few decades later, people were sending each other cards for Christmas, Easter, and on their birthdays, as the greeting card became a fixture of American life.[1]

In a lot of ways, the development of email has followed the same course that the postal system did. For one thing, the implications of the new system weren't clearly understood at first -- the first email software was originally designed for transferring files and programs over a network. And once email and other forms of electronic communication became widely available to the public, they were rapidly adapted to almost all the purposes that cheap mail had served. They ushered in a new age of personal communication, but they also facilitated swindles, junk mail, pornography, and anonymous hook-ups and erotic connections. In short, email is used for everything that delighted and troubled observers of the postal system in the mid-19th century.

But following on the heels of cheap long-distance rates, email put the final kibosh on the personal letter. Nowadays, the only personal messages that most people will regularly go to the trouble of putting in the post are the ones that serve a ritual function, like thank you notes, letters of condolence, or greeting cards. True, you can send a valentine electronically, and some sites will even let you do it anonymously, though you might want to think long and hard about plighting your troth to anybody who's stupid enough to open the attachment on an anonymous email. But for most of us, those kinds of messages can't do their magical work if they don't physically originate with the sender. It's like getting an electronic postcard from friends who are visiting Turkey -- it may be nice to hear from them, but you're not going to print it out and stick it on your refrigerator door.

Those remaining postal rituals are a vestigial sign of the allure that letters once exerted on the American imagination. In fact letter is about the only word for correspondence that has resisted digitization. We talk about email and electronic notes and messages, but sending a letter still means putting a piece of paper in an envelope. It's true that nowadays the only pieces of paper we can expect to find in our mailboxes that bear a handwritten signature were generally printed by Hallmark. But maybe it's appropriate that the cards that signaled the opening of the postal age should be among its last remnants as it draws to a close.