Easter and William Asmus had only been married three months when a petty dispute over theater revealed deep betrayal.

On 5 November 1918, Easter attended a play, Where Poppies Bloom, a drama portraying German “intrigue” during the first world war. When Easter got home, she started to tell William all about it. William “flew into a rage and told me I was not to see any war shows; that he was a German and that I, as his wife, was accepting the bounty of a German.”

Easter was horrified. When the New York City couple married, William had insisted that he was a US citizen. By marrying a German, Easter “was deprived of her American citizenship and to her great mortification and disgrace, became a subject of the Emperor of Germany, and an enemy alien of the United States of America.”

Easter left their home that day, possibly facing poverty and estrangement from her country. Easter’s next move was perhaps more shocking than her husband’s treachery, given the era: she decided to seek an annulment and alimony of $35 a week, according to court documents.

Easter’s long-ago predicament surfaced after reports about a phenomenon said to be playing out amid Covid-19: pandemic divorces. Reports described a seeming surge of divorces, separations and sundry splits across the US during coronavirus pandemic. The narrative behind this purported trend is that spouses and partners, stuck at home with their significant others, saw minor annoyances snowball into active hatred and long-simmering resentments turn unsustainable.

Much like contentious romantic splits, however, the existence of this specific pandemic-spurred social shift remains a matter of contention. While reports present anecdotal evidence that more people are fleeing their partners – or planning to do so – data doesn’t universally support this.

Bowling Green State University researchers Krista Westrick-Payne and Wendy D Manning examined divorce rates during the pandemic and took into account whether pandemic deaths could account for any decline in divorce filings. They found that there was a 12% drop in divorces in 2020.

These reports and data, however conflicting, nevertheless made some wonder: what were splits like during the 1918-19 influenza pandemic, which also ravaged the US?

A sampling of New York City court documents – which had been sealed for 100 years, and obtained after about 18 months of requests – provides remarkable insight into this. Even as the pandemics ravaged the US a century apart, some of the same issues played out in the divorce courts: colorful language and breathless moralizing showed that marital mudslinging is timeless and immune to disease, even if the spouses were not.

They also offer a remarkable glimpse into life in New York more than a 100 years ago, at a time when getting a divorce – for a brave woman – was a risky business full of social disapproval and huge economic risk.

In addition to Asmus, another unhappy wife of the early 20th century was Celia Abramovitz, a dressmaker who filed for divorce against her husband, Isidore, in February 1919. Celia alleged that Isidore had committed adultery with women since they wed in 1910 – a New York City lover starting in 1913, and a Montreal, Canada, paramour beginning in 1914 – and said she wanted out of this international love quadrangle.

“Said acts of adultery were committed without the consent, connivance, privity, or procurement of the plaintiff,” court papers stated. More, Celia alleged that the Bostoni, Romania, native lived with his lovers, including one “during the entire year of 1918”.

Witness testimony in Celia’s case revealed the breadth of this betrayal. Jacob Golfman, a “woolens and silks” merchant from Montreal who had known Isidore for three years, said that Isidore introduced him to his wife “after a while”.

Isidore lived in Montreal with this woman under the same roof and there were three children, whom Isidore introduced as his own, and described her as his wife to “tens of” other people. Golfman once happened upon Isidore, undressed, and his apparent wife in their bedroom.

“Is that the lady on the stand?” Celia’s attorney asked.

“No, sir, this lady I never saw before with the exception of here in New York.” Golfman learned that the Canadian woman wasn’t Isidore’s wife when he was “arrested and all in that case”.

Isidore did not mount a defense against Celia’s divorce petition. A judge found him in default and granted her request.

There were spurned husbands, too. Some, like Frank Allen, used relatively plain language in their petitions. Allen, who on 16 December 1918 sought separation from his wife, Mary said that she treated him “in a cruel and inhuman manner in that she committed adultery” over the past year.Mary, he said, “conducted herself as to render it unsafe and improper for [him] to cohabit with her”.

But some jilted husbands, such as Arthur Alton , had more sensational petitions.

On 22 November 1918, Arthur Alton sought divorce from his wifeAnna claiming that she had cavorted with another man for several years. One day prior, the accused adultress was allegedly caught in the act.

Myron Avedikian, an acquaintance of Arthur, traveled with him and several others to Anna’s alleged love nest on Manhattan’s Upper West Side. The party rang the bell.

“They answered and they opened the door. We went in together and we saw them – the door open[ed] in the dining room, we saw them both together in the dining room,” Avedikian said in a deposition.

“You saw the defendant Anna Alton in a room with a man who was not her husband?” Alton’s lawyer asked. Avedikian answered in the affirmative and said that the dining room opened into the bedroom – which had only one bed.

“Mrs Alton was dressed – not very good clad, only had an apron and underneath the apron, I don’t think she had much,” Avedikian said. The lawyer asked: “Did she have her stockings on?”, to which Avedikian replied, “No.”

“The apron had only one button at the back, so you could see the bare back of her.” The man “had no coat on and was buttoning his pants” when Avedikian and Arthur arrived at the home. The bed, Avedikian said, “wasn’t fixed very nice, certainly”.

When Arthur revealed he was Anna’s husband, the man “fussed, but after a while, they started to talk, and they said not to make any noise while doing down”.

On 12 August 1919 Arthur got his wish. A judge entered a judgment “dissolving the bonds of matrimony … and freeing the plaintiff from the obligations thereof, and permitting the plaintiff to remarry but forbidding the defendant from remarrying any other person during the lifetime of the plaintiff “except by express permission of the Court”.

While it’s not surprising that this matrimonial paperwork would be written in such impassioned terms – divorces, separations and annulments are emotionally tense – there was a legal reason behind this as well. Before 2010, New York state did not have “no fault” divorce, meaning that one spouse had to accuse the other of “adultery, cruelty, imprisonment or abandonment”.

Nancy Chemtob, a matrimonial attorney whose high-profile clients have included Mary-Kate Olsen in her split from Olivier Sarkozy, said that a spouse was required to provide proof, this dragged out the proceedings in a way requiring proof of these factors. “I want to get divorced, I don’t like my husband – OK, well, that’s not going to work,” Chemtob said of the days before no-fault divorces.

A wife could accuse her husband of cruelty, but ultimately fail to get a divorce if he professed love on the witness stand. One spouse could accuse another of adultery, while the other could respond with a blanket denial of this claim. “How do you prove that?” Chemtob said.

Michael Stutman, chairman of the New York City Bar Association matrimonial law committee, pointed out that even when marriages did end, women were at a dramatic disadvantage.

“In some states, in the event the female was found to have behaved in certain ways during the marriage before the divorce, that could disenfranchise her from any claim of support as well – while that same conduct, if evidenced by the male, by the husband, he suffered no consequence.”

The ultimate impact of Covid-19 on divorce rates remains unclear – the pandemic hasn’t ended yet – but statistics from the influenza pandemic provide interesting historical context. In the five years leading up to the influenza pandemic, there was a gradual increase in divorce rates.

In 1913, divorce rate was 0.9 per 1,000 people. In 1914 and 1915, that number climbed to 1.0. In 1916, the rate went up still more, to 1.1 and in 1917, it reached 1.2 per 1,000.

Then came the influenza pandemic. There was a dip in 1918, to 1.1 per 1,000, but in 1919, it rebounded to 1.3. After that, the divorce rate continued to trend upward, even with periodic dips, peaking in the 1950s, according to CDC vital statistics.

Ranjit Dighe, professor of economics at the State University of New York at Oswego, said that increase in divorces in the late 1910s and 1920s came amid tremendous social upheaval about gender roles.

Dinhe noted that Congress voted to give women the right to vote in 1919, a legal decision that was ratified in 1920. This, in turn, might have contributed to the dramatic rise in divorces. “You probably had more women who were a lot more independent-minded.”

As for a dip in 1918, Dighe said he would be surprised if the influenza pandemic itself had much of an impact in divorce, as some claim Covid-19 has had. “You didn’t have a lot of people quarantining, couples kind of jammed together,” Dinge said, as officials “really tried to sweep it under the rug”, even more so than early on in Covid.

However, the influenza pandemic might have addressed marital woes in another way. “It’s entirely possible that some couples that would have been divorced didn’t have to, because one was dead,” Dighe said. “Bad marriages might have ended in death because of influenza.”