A century ago, America celebrated the holidays under the shadow of a deadly pandemic. Here's everything you need to know:

What was the mood then?
In many ways, Americans were worse off than we are now. The nation had just endured the second, and by far the deadliest, wave of the Spanish flu pandemic, caused by the H1N1 virus originating in birds. The initial wave had started the previous March, spreading from an Army base in Kansas, but it was relatively mild, with a low death rate. When the virus reared its head again in September, though, it had mutated into a far deadlier strain — one that killed victims within days or even hours of the onset of symptoms. Their lungs filled with so much fluid, blood, and mucus that victims essentially drowned, and their skin often turned blue. This strain hit the young and healthy particularly hard. In October 1918 alone, an estimated 195,000 Americans died — a staggering death toll given that the U.S. population was less than a third of what it is now. But the wave swept through fairly quickly, and by December there was a sense that the threat had largely passed. "The holiday spirit is abroad in the land," wrote The Salt Lake Tribune, "and the 'flu' is not so much of a menace as it was a few weeks ago." There was another cause for celebration: the end of World War I.

When did the war end?
An armistice was agreed to on Nov. 11, ending a brutal ­conflict in which some 116,000 U.S. servicemen died (though more ­succumbed to the flu than to actual combat). So the nation was feeling celebratory in spite of the flu's carnage. "The mood was absolutely euphoric for most of the country," said historian Kenneth Davis, author of a book on the pandemic, More Deadly Than War. In his Thanksgiving proclamation, President Woodrow Wilson spoke of the nation's "special and moving cause to be grateful and to rejoice." In New York City, where thousands of returning servicemen were arriving by ship, "Yuletide will be a time of rejoicing over victory," wrote The New York Times on Christmas Eve. The city was rolling out the red carpet with vaudeville shows, dances, sightseeing buses, and "Christmas tree parties," the paper wrote, saying there should be "no unfed or unentertained man or woman in this city."

So Christmas went on as usual?
Then as now, the need to celebrate was balanced with a healthy fear of contagion. Stores were mostly open, but the Council of National Defense decreed that shopping should be done early and limited to "useful" gifts, and health officials ordered department stores to curb crowd-gathering displays featuring Santa Claus. "Santa Claus Is Down With the Flu" read a Dec. 6 headline in the St. Paul Daily News. While many restrictions put in place at the height of the fall wave had been relaxed, church services were still barred in many locales, and major Christmas events were canceled, from Milwaukee's tree-lighting ceremony to Denver's Salvation Army Christmas parties to holiday school assemblies in Fall River, Massachusetts. A Columbus Evening Dispatch story detailed how the "influenza ban" had "dealt a severe blow to Christmas plans," quashing many "delightful entertainments." Caroline Schumacher of Carroll, Iowa, wrote in a letter that "it is terrible when there's no church. It didn't seem like Christmas at all."

Did families gather?
That was less a point of contention then than it is now — perhaps in large part because extended families generally lived together or in close proximity, and few traveled far to share a Christmas roast. But that doesn't mean concern was absent. "Beware the mistletoe," read a warning from the Ohio health commissioner. "You will show your love for dad and mother, brother, sister, and the rest of 'em best this year by sticking to your own home instead of paying annual Christmas visits, holding family reunions, and parties generally." In a manner that feels distinctly familiar in 2020, the police chief in Fresno, California, hedged his cautionary words by making clear he had "no desire to interfere with anyone's freedom or fun." Still, he felt compelled to point out that not "assembling indoors would do much toward checking the further spread of this epidemic that is causing so much sickness and death."

What happened afterward?
Lots of new infections, with the pandemic's third wave beginning in January. It wasn't nearly as virulent as the second one, but nonetheless it killed tens of thousands more Americans. In Seattle — where a November Seattle Times headline had trumpeted "Epidemic Virtually Over" — half of the roughly 5,000 city residents who died of the flu were stricken after Christmas. "I helped lay away more people this winter than I ever did in all my life," John Tinti of Iowa wrote of burying friends and neighbors. "It sure was awful." By the time it petered out in summer 1919, the Spanish flu had killed an estimated 675,000 Americans — and more than 50 million people worldwide.

A debate over masks
As Christmas 1918 approached in San Francisco amid a continuing flu pandemic, the city was caught up in a fervid debate: Should citizens be made to wear masks? Two months earlier it had been the first U.S. city to pass a mask law, backed up with a fine of $5 or up to 10 days in prison. But resistance was wide and strong. Opponents called the masks uncomfortable, unsightly, and an impingement on their freedom, and hundreds of resisters were arrested, requiring extra police shifts. When the law expired on Nov. 21, people celebrated and threw their masks into the street. As case numbers rose and Christmas loomed, the city reconsidered a ban, but amid fierce opposition it was voted down on Dec. 19. Weeks later a surge would bring a reinstatement of the ban, giving rise to an Anti-Mask League. But for Christmas at least, residents were free to go barefaced, to the chagrin of public health director William Hassler. "The dollar sign," he lamented, "is exalted above the health sign."

This article was first published in the latest issue of The Week magazine. If you want to read more like it, you can try six risk-free issues of the magazine here.