For all the talk of ending Saturday mail delivery, it came as something of a surprise when the Post Office announced that it would start delivering on Sunday. But that’s just what it did this week, reaching an agreement with Amazon.com to deliver the online retailer’s packages to Amazon Prime members on the Sabbath. As the indispensable Megan Garber points out at The Atlantic, “the move will mark the first Sunday mail delivery the U.S. has seen, with a few exceptions, for a century.” In fact, the history of Sunday mail may be even more interesting than the Amazon announcement itself.

Garber points us to historian Claude Fischer, who documents the central role post offices played in early American life. No less a man than Benjamin Franklin was the first Postmaster General, after all, and the federal mail system linked all the parts of the nascent country together, facilitating the free flow of news, messages, and business. “Post offices themselves were important community centers, where townsfolk met, heard the latest news read aloud, and just lounged about.” Home delivery wouldn’t even emerge in the largest cities until after the Civil War.

As Lee in John Steinbeck’s East of Eden said about the 1910′s, “We never get any mail in mid-afternoon. Nobody does. But every man in Salinas goes to the post office in the afternoon.” The source of connection to the greater nation, in perhaps some contrast to Patrick Deneen’s theme last week, was the hub of locality and community.

Those pivotal local post offices had often held Sunday hours, but Congress codified it in 1810, requiring that post offices be open for, at minimum, one hour each Sunday. That’s where the story really gets interesting. For “in the 1820s, established church leaders, notably New Englanders and Presbyterians, campaigned to close post offices on Sundays. Doing business desecrated the Sabbath, required postal employees to violate their beliefs, and generally undermined the Lord’s day of rest.” What’s more, “in some communities, the post office was the only place other than church that was open on Sundays, so men would rush there as soon as the mail had arrived, staying on to drink and play cards.”

The stern Calvinists believed in a strict Sabbath, one whose rest from work would not be wasted on wickedness or distraction. Businessmen fought them off, however, as even the early 19th century life often held up as a model of agrarian patience felt a compulsion to not miss a single day’s time in conducting its commercial affairs. The merchants found an ally in “some evangelical ministers, particularly Baptists,” who had grown during the Second Great Awakening, “and among secular laymen who saw the sabbatarian drive as a power grab by high-status, eastern churchmen.” Fischer relates that “the conflict became further inflamed with the increasing immigration of Catholics, many of whom celebrated ‘Continental’ Sundays which included all sorts of secular pleasures – picnics, even beer halls – after (or instead of) church.” So community and church competed for the attention of their citizens.

Business interests and low-churchers kept America’s latter-day Puritans at bay throughout the 19th century, and men could continue to congregate in the mid-afternoon, even if (especially if) no mail was coming. Change was in the air, however, by the turn of the century, even if it had yet to fully reach Steinbeck’s Salinas Valley. The progressive era revived and revitalized American moralism, with voluntary associations like the Anti-Saloon League and the Lord’s Day Association advocating their own legislative solutions to American dissolution. Finally the Puritan’s heirs were able to make an alliance of their own, this time with the growing labor movement.

Both motivated by reaction to the upheavals and demands of industrializing America, the union leader seized on the church crusader’s Sabbath as part of his effort to carve out at least one day of rest from the factories’ seven-day work week. Technological changes like the telegraph and the telephone kept business humming without physical deliveries, easing the mercantile opposition. In 1912, Congress passed a rider on an appropriations bill banning post offices from conducting normal business on Sundays.

One century and one year later, a very different world is sweeping out the Sunday dust in the U.S. Postal Service. In the interim Sears and Roebuck went from direct mail pioneers to anchoring commercial centers and naming great buildings. Today, Sears struggles in the brick and mortar as Amazon innovates in its place. From a hub of community and interwoven connection, the post office has become an efficient waystation in the advancement of the frictionless online marketplace. And the speed of information businesses pay for is measured in fractions of seconds.