This is the story — kept secret at the time, still largely unreported today — of how the most infamous disease in history broke into New York City in the midst of World War II. This is the story of the ominously-named “Wyoming matter,” and how it took me months to track down evidence it ever happened.


I wasn’t looking for this story. I bumped into it reading Up in the Old Hotel, a collection of old New Yorker stories from ‘40s, ‘50s, and ‘60s all written by Joseph Mitchell. It’s a great book, very neatly written, filled with lots of snapshots of life in the city’s most romanticized era.

And there’s also a detailed description of how it was all at risk of infection by the disease that killed some 50 million people in the 14th century.


In 1944, Mitchell wrote the short essay ‘Thirty-Two Rats From Casablanca’ for the New Yorker (later republished in Up in the Old Hotel), which describes the hellish presence of brown rats in the city. There are lamentations from city health inspectors, rat-filled nightmares by city drunks, and horrifying descriptions of day-to-day humanity sharing space with rats.

There’s a particularly memorable line about a stableboy who tried to kill a rat on a West Side riding academy with a broom handle. The rat scampered up the handle and tore a thumbnail off the kid’s hand, in broad daylight. Think about that the next time you find a rat in your apartment.



Worse than these passages are the notes on how the rats carry plague, and how their populations in port cities spike in times of war — which, mind you, was very much raging in 1944. One consultant on the staff of the Department of Health gives a lengthy description of how many plague-carrying fleas live on the average rat and how many are found on the average ship.


He concludes with the line “I don’t care to generalize about this, but I will say that if just one plague-infested rat got ashore from a ship at a New York dock and roamed for only a few hours among our local, uninfected rats, the resulting situation might be, to say the least, quite sinister.”

Sinister. That’s not a word you use lightly.

How Plague Beat New York’s Quarantine

Mitchell continued his essay noting how few bubonic plague outbreaks there had been in the United States. We only had a few recorded incidents, pretty much all on the West Coast and none worse than the bungled 1900 San Francisco flare up. Mitchell then changed his tone and began the description of NYC’s brush with the Black Death.

There has never been an outbreak of the plague in New York. There have, however, been two narrow escapes. In 1900, plague-infected rats were found in ships in the harbor of New York, as well as in the harbors of San Francisco and Port Townsend, Washington. They got ashore only in San Francisco, causing the first Black Death epidemic in North America. Plague rats were found in New York Harbor for the second time early in January of 1943. Among themselves, health officials refer to this discovery as “the Wyoming matter.”


Emphasis mine, because “the Wyoming matter” is the most amazing name for a disaster that has not yet been turned into a Hollywood blockbuster. Mitchell claims that he was the first to learn about the incident. In his article, he says he heard about it a year later in 1944 when he met with Dr. Robert Olesen, the medical director of the New York Quarantine Station of the Public Health Service.

“The Wyoming matter has been one of the best-kept secrets in the history of the Public Health Service,” Olesen told Mitchell. Olesen added, “there’s no reason to keep it secret any longer.”


The job of the Quarantine Station was to keep infectious diseases out of the busy (and strategically important) New York City ports. They looked through cargo coming from other ports with recent outbreaks, they checked ships for clean bills of health of their sailors, and they did quite a lot of work in ratproofing.

Mitchell recounts an explanation from Dr. Olesen of how the Public Health Service inspected ships back then. Ships were boarded by six different inspectors from six different services, looking and smelling for rats. (Rats are described as having the same smell as cats, only not as bad.) The officials used tear gas to flush out any hidden stowaways and then unleashed hydrocyanic gas. That’s what killed the rats.


Officials then plucked out the dead rats, combed them for fleas and snipped out their livers. The fleas and the livers got ground up, mixed into solutions, and then injected into guinea pigs. If those guinea pigs got the plague, you knew you had an infestation.

For 22 years, Dr. Olesen explained, the Quarantine Station staff regularly carried out these guinea pig plague injections and no bubonic plague turned up. They felt their work was “routine and futile.” Olesen’s description of how things went pear-shaped probably had quarantine station workers wishing for their usual tedium.

Now then, late in the evening of January 10, 1943, the French freighter Wyoming arrived from Casablanca, North Africa, with a miscellaneous cargo, mainly wine and tobacco. A big convoy came in that evening, sixty or seventy ships, and we didn’t get to the Wyoming until the next day. Casablanca was on the plague list at that time; there had been an outbreak in December, shortly before the Wyoming sailed. The crew was carefully examined. No sign of illness. Then the captain brought out a de-ratization certificate stating that the ship had recently been fumigated — in Casablanca, if I remember correctly — and was free of rats; looking back, I feel sure the official who signed this certificate had been bribed.


Olesen then described how the ship was allowed to dock in Brooklyn and Manhattan, and how some longshoremen spotted rats near her. Officials then fumigated the ship, scoured it for rat corpses, and performed their flea-and-rat-liver pâté test on two guinea pigs.

Both guinea pigs sickened and died.

This was it, confirmation that plague-carrying rats had reached New York. The city had been breached, and the Quarantine Station was one step behind a potential outbreak.


The Quarantine’s Secret Extermination



By the time the Quarantine Station confirmed that the Wyoming had brought plague-infested rats into New York, it was January 29th and the Wyoming had moved to Staten Island for repairs. They ripped open the inside of the ship, pulled out all of its gear and opened every enclosed space in the holds. They refumigated, killing another dozen rats.

On the same day we got in touch with Dr. Stebbins, the Commissioner of Health for the city, and told him about the situation. We were terribly apprehensive. The Wyoming had touched at piers in rat infested sections in three boroughs and there was, of course, a distinct possibility that infected rats had got ashore and were at that moment wandering around the waterfront, coming in contact with local rats and exchanging fleas. Mr. Holsendorf, in his capacity as the Health Department’s rat consultant, quickly got together some crews of trappers and put them to work setting break-back traps on the the Brooklyn pier, the Manhattan pier, and the Staten Island pier, and in buildings in the vicinity of each pier. The trapping was done unobtrusively; we were afraid a newspaper might learn of the matter and start a plague scare.


Secret rat trappings! This was getting good. The Quarantine officials then broke from the normal protocol and sent their first rats out for autopsies at local hospitals in early February, rather than at their laboratory. Working with nearby hospitals was faster, and time was of the essence.



We waited for the report with considerable anxiety. It was negative on every one, and we began to breathe easier. Mr. Holsendorf and his crews trapped from the end of January to the middle of May and the reports continued to come in negative. At the end of May we concluded that no Wyoming rats had got ashore, and that the city was safe.


But no rats had got ashore, he wrote.

And that’s the story of the Wyoming matter. Plague-bearing rats made it all the way up to New York City’s piers but unbelievably did not spread their disease to the city’s local rat population. You could say thankfully, you could say miraculously.


Researching An Outbreak Avoided

New York City had every reason to be hit with the Black Death and it somehow scraped by. Where things get particularly strange is why you haven’t heard anything about the Wyoming matter since it happened. Furthermore, Joseph Mitchell had a reputation for “mixing fact and fiction,” as a very recent profile from the Atlantic states. The guy isn’t exactly a reliable source.


That meant that I had to confirm this history myself, and that process turned out to be just as bizarre as the actual event.

The first thing I did was look for other references to the Wyoming matter. I quickly discovered that Mitchell’s account is pretty much all that has been written about the incident. The excellent book Rats, Observations on the History and Habitat of the City’s Most Unwanted Inhabitants mentions the story, but the only reference is Mitchell’s article. The New York Times left out the Wyoming matter entirely in a 2004 report on rats in the city, as this letter to the editor implies.


I got in touch with Dr. James Colgrove at Columbia, the man who literally wrote the book on epidemics in New York City, in the hopes that he’d have some confirmation of the story. Not only had he never heard of the incident, he couldn’t find any reference to it in his personal library. He told me “it doesn’t sound as if the episode was significant enough to have garnered any sustained attention” as an explanation.


With nothing turning up in academia, I followed in Mitchell’s footsteps; I went to the Public Health Service. Only the Public Health Service isn’t the Public Health Service any more. It’s the Department of Public Health. Changes in federal administration, I was soon to find out, were going to make my investigation very difficult.


Getting ahold of the Department of Public Health was simple. They told me they’d look into their records to see if anything turned up. A few very eager weeks and several follow-up voicemails later I got a call. They didn’t have anything in their diseases archive on the Plague. Nobody in New York actually contracted the disease, they explained, so there wasn’t any record of it being here. I was looking for evidence of an outbreak that never happened.

Even so I was quite confident that something would turn up. I figured the next place to look would be the Quarantine Station itself. Surely they would have some record of their own successful defeat of the most infamous disease in human history. I called the library at the Center For Disease Control, since they’re the agency that oversees Quarantine. An impossibly kind man answered the other end of the line (he’s a Jalopnik reader!) saying he and his coworkers would leave no stone unturned looking for a reference to the Wyoming incident.


Days later I got a very polite call stating that the CDC’s records don’t go back far enough to cover the event. They came up short by decades.

Several more calls and waits and voicemails later I ended up speaking with Don Spatz, the Officer In Charge of the CDC in Greater New York.


“In 35 years I’ve never heard of it.” Spatz immediately admitted that he knew nothing about it, there was nobody left who was working in quarantine at the time, and the retrospective book he had on the station’s history didn’t have anything I mentioned to him. Looking further would be difficult for me, he explained, because of the particular nature of the Quarantine Station’s authority.

They were housed under the Department of Health and Education, Spatz explained, and before that they were under the U.S. Treasury Department. Before that they were with the Public Health Service, which joined with Quarantine under the Dept. of Health Education and Welfare, then they ended up in the CDC in the ‘60s. Back in the 1940s, Spatz told me, they were with the Federal Security Agency. I looked them up and, I shit you not, the FSA served as a cover agency for the War Research Service, which was a secret biological weapons project by the government.


Spatz had no absolutely idea which agency would be responsible for housing any Quarantine Station records from the ‘40s at this point.

Almost completely out of ideas, I called the National Archives. Another very nice operator picked up, and listened to me once again relay every detail I had about the Wyoming matter in the hopes that somebody would have any idea where a record would be kept. “Lord have mercy,” she gasped over the phone when I got to the part when the rats tested positive for the first time in 22 years of lab work.


She told me to email her supervisor, and her supervisor sent me to the National Archives in New York, and that’s when I got the phone call.

The Threat Of Plague Was Real

The National Archives at New York City did indeed hold the records for the New York Quarantine Station, and a search through their records turned up something by Olesen mentioning plague and the Wyoming specifically. They were located a few subway stops down from my office.


I made an appointment as soon as possible and quickly found what I was looking for. Tucked into the station’s complete record of their Quarantine Transactions were these two lines from a monthly report.

GUINEA PIG INOCULATED JAN. 1 1943, FROM A POOL OF 12 FLEAS (X. CHEOPIS) RECOVERED FROM RATS KILLED BY FUMIGATION OF THE FRENCH S/S “WYOMING”, RESULTED IN THE DIRECT RECOVERY OF A PURE CULTURE OF PASTEURELLA PESTIS. GUINEA PIG INOCULATED JAN. 19, 1943 FROM POOLED TISSUE OF 15 RATS RECOVERED FROM FRENCH S/S “WYOMING”, RESULTED IN ULTIMATE RECOVERY OF A PURE CULTURE OF PASTEURELLA PESTIS.


Pasteurella pestis (now referred to as Yersinia pestis) is the scientific name for the plague, and this was the first time I was seeing it in an official government document. I found further confirmations in a handful of other documents. The 1943 annual lab report gave the precise counts of the damage (15 plague infected rats and 12 fleas). Finally I had a government record clear enough that I wasn’t relying on Mitchell’s words alone. Our threat of plague was very real.

Accused Incompetence And An Unfinished Report

A letter dated March 10, 1943 from the City of New York’s Health Commisioner Ernest Stebbins, however, cast some confusion over the matter.



Dear Dr. Olesen: Thank you very much for your letter of March 6, and the copy of your letter to the Surgeon General. I am sorry that you were not able to obtain confirmation from either laboratory. We are, however, continuing the trapping to obtain samples of the rat population which without question will be adequate to demonstrate the fact that plague has not been introduced into New York City. Sincerely yours, Ernest L. Stebbins, M.D. C o m m i s s i o n e r.



This implies that at some point during the extraordinary lab work, outsourced from the Quarantine Station to local hospitals, somebody failed to get a confirmation that plague really resided in any rats.




Furthermore, I found a troubling line in Olesen’s 1943 annual report. Under the subheading ‘Plague Infection,’ he briefly details the Wyoming matter, but implies that there was more evidence of plague getting around, evidence that was lost.

THERE IS NOT THE SLIGHTEST DOUBT THAT PLAGUE INFECTION WAS ENCOUNTERED BOTH IN FLEAS AND IN RAT TISSUES AFTER THE FUMIGATION OF A VESSEL WHICH ARRIVED IN JANUARY, 1943. HOWEVER, OWING TO INCOMPETENT LABORATORY PROCEDURES IT WAS UNFORTUNATELY NOT POSSIBLE TO SECURE CONFIRMATION OF THIS IMPORTANT FINDING. A COMPLETE ACCOUNT OF THIS OCCURRENCE HAS ALREADY BEEN SUBMITTED.




Olesen goes on to describe a lack of staff at the Quarantine Station’s labs as “particularly embarrassing.” Indeed he complains many times about staff shortages and trouble with maintaining his operations during World War II. He particularly stresses the how his work has been “intensified and complicated” by convoys both because of their volume (“sometimes as many as 60 ships in a few hours”) and their need to maintain some secrecy about wartime movements. “Therefore it is impossible to institute preliminary infestation inspections without seriously dislocating the war effort,” Olesen describes in a report, pointing the fundamental weakness of the Quarantine Station to keep plague out of New York.

I flipped ahead to the annual report made by the ship sanitation division and the ‘Laboratory’ subheader.

The routine examination of rats and their ectoparasites for evidence of plague infection was continued. Plague infection in rats and fleas was demonstrated to exist on one vessel entering the Port of New York from Casablanca, Africa. A special report of all the circumstances and findings was made.




A complete report was made! This was a huge breakthrough. The only problem was that I didn’t have this report and I couldn’t seem to find it in any of the archival documents I’d pulled.

So I took two more days, and I checked every single file that could possibly maybe tangentially be related to the plague. I read everything from a letter written by Olesen wherein he dissed a novice reporter at Pic magazine for publishing an error-filled article that could have been better written by “a fifth grade pupil” to an individual $3.70 bill for King Syrup for the Quarantine Station’s quarters. There was no sign of the mysterious complete official report.


And then I realized that the document I was looking for was the very first one I saw at the archive. I just couldn’t believe that it was the official report.


Here’s why I didn’t realize what I had first seen was what I needed all along. There are only three pages, printed on the back sides of scrap paper, heavily edited by hand. The first two pages introduced the events as I had already heard them, and the third seemed to set up a discussion of the difficulty in the rushed lab work. And then, halfway down the page, the report ends mid sentence.



“The infestation inspection of the ‘Wyoming’ was undertaken,” and it stops there. No further clarification of how the fleas were processed, or how the lab report may have been screwed up, or how exactly they campaigned to keep the incident secret, or why they did not wish to go public now that the whole mess was over.


You cannot make this shit up.

There is no doubt in my mind that the Wyoming matter happened. The only thing that’s still missing are the exact details of how these plague fleas got analyzed. Is that why this incident hasn’t been championed by the Quarantine Station, the Public Heath Service, the government altogether? I have no idea.


I’d need to find the final version of Olesen’s report. I have no idea where it is or if it exists.

Now, it’s hard to know exactly what to take away from the Wyoming matter. It certainly isn’t complete trust in the government’s system of containing plague at the time. The Wyoming did get into New York and it did so carrying plague-ridden rats, and it allowed those plague-carrying rats to intermingle with the omnipresent rat population of ultra-dense lower Manhattan, as well as Brooklyn and Staten Island.


After going through all of these documents, it seems more like luck than anything else that kept the city from the most infamous disease in history.

The other question that remains is this: how much of a crisis was actually averted? Well, that’s also hard to say, since there aren’t too many plague outbreaks in modern American history to compare it to. But if you go on the only one we do have, things don’t look so great.


Grim Lessons From America’s Other Outbreak

Much of why I have little trust in the idea that the government would be able to totally control things in New York City had the Wyoming rats let their fleas galavant through the city blocks is because of the spread of the plague in San Francisco 1900.


This was the first recorded case of plague in the continental United States and, not shockingly, it did not turn out well. Particularly worrying is not how the bubonic plague spread from Hong Kong to San Francisco’s Chinatown. What’s troubling about that history is how everything was covered up.

As the aforementioned book Rats details, the Chinatown community hid their plague-ridden corpses from local inspectors, fearing punishment. There’s a description of one dead family member being propped up Weekend At Bernie’s-style with his hands over dominoes to fool investigating physicians.


This was understandable. Racist politicians were all to happy to advocate burning Chinatown to the ground. Rumors spread that any Chinatown resident seen going to the plague detention camp the city set up on an island in the harbor would be killed. Even when the local government and businesses found out, they and the California governor tried to suppress any knowledge of the plague. They feared a a boycott of San Franciscan goods, decline in rail travel, and a sharp loss in tourism.

And the San Francisco elite did an extremely good job. They got the press (including William Randolph Hearst’s The Examiner as well as the Associated Press) to claim the plague was merely a scare and a fabrication. They got the quarantine of Chinatown lifted. They went so far as to accuse the top contagion expert in the country (fortuitously working in San Francisco at the time) of planting the plague on the patient zero found in a flophouse. They eventually got him reassigned to Detroit in the midst of the crisis.


What’s particularly troubling is that we still have sporadic cases of the plague in the middle of the U.S. and they all stem from rodents that caught Yersinia pestis originating in San Francisco 1900 as this article explains. Plague spread from San Francisco to the rodents of California, and those rodents continued to spread the disease deeper into the country. As the book Rats notes, there are more rodents currently infected by plague than there were in Europe during the time of the Black Death. All that differentiates now from then is that our plague-carrying rodents tend to live in very sparsely-populated areas. I’m talking about plague-carrying prairie dogs, here.

Even so, a teen died of the plague a few months ago, an unnamed adult died a week ago, and another man is recovering as we speak after picking up a flea from a dead chipmunk in his backyard. Those are in Colorado only. A kid in Los Angeles County caught the plague only a few days ago.


Had plague caught on in the crowded streets and apartments of Brooklyn and Manhattan (incidentally the Wyoming landed not far from two of the city’s current Chinatowns) 70 years ago, it’s safe to assume that it would have continued to spread out through the rest of the country. That’s what it did after San Francisco; that’s what it would have done if it had stuck in deeper into New York. And the East Coast is much denser than the West, let alone the 1940s East compared to the 1900s West.

So be very thankful that the Wyoming matter turned out the way it did, and if you see a copy of that full report, please let me know.


Image Credit: Jim Cooke