President Trump threatened to quarantine New York. Though he impulsively dropped the idea, other states, like Rhode Island, are apparently running with his ill-conceived notion, with Gov. Gina Raimondo ordering law enforcement to “pin point” New Yorkers in the state and force them to quarantine.

These misguided acts depend on the false idea that certain populations are carriers of illness, even though science has shown that the illness is already present and rampant throughout the country. Keeping New Yorkers in quarantine cannot protect the country from the coronavirus that is already spreading throughout American communities. But it will further fuel xenophobic ideas of how disease spreads and is best combated. Trump’s demonization of New Yorkers distracts from a full discussion of what the federal government could actually do to shore up the country’s health-care infrastructure. Instead he chooses to stoke America’s biases about all that New York represents.

This is not the first time a president of the United States involved himself in quarantining New York. Over a century ago, in September 1892, Benjamin Harrison issued the first executive order in history to quarantine a group arriving in New York harbor, using open anti-Semitism to cast Russian Jews as a national health threat. Historically, one of the deadliest mistakes in public health policy is to associate a disease with a particular “undesirable” segment of the population. In our nation’s history, the traditional scapegoat has been immigrants. Trump extended it to all New Yorkers. Repeating this mistake today will have deadly consequences for all Americans.

Indeed, this was the case in August 1892, when several ships originating from the cholera-infested port of Hamburg, made their way toward New York. Cholera, a disease whose symptoms include sudden cramping, vomiting, violent diarrhea and rapid dehydration that often lead to death, had spread through, Russia, India and the Middle East. At the time, people mistakenly believed it could be passed from person to person, when in fact cholera is not airborne but is caused by eating food or drinking water contaminated with a bacterium called Vibrio cholerae.

The fear of cholera coincided with the arrival of a large number of East European Jewish immigrants, who all set sail from Hamburg. While the first-class section of the ships was filled with members of New York’s wealthy elite returning from European vacations, immigrant Jews filled the steerage class. Indeed, between 1880 and 1892, the average number of Jewish immigrants from Russia, Poland, Romania and Austria-Hungary grew from about 6,000 per year to well over 75,000. As a result of famine and economic hardship in their homelands, by 1891, Eastern European Jews represented 13.2 percent of total immigration to the United States.

While not emphasizing the Jewish character of the immigrants, the New York Times declared on Aug. 29, 1892: “With the cholera killing people by the wholesale in the ports whence these creatures assemble to take passage to the United States, there is good ground for the present demand for absolute prohibition of immigration.” The New York Herald was less discrete as it emphatically proclaimed that Russian immigrant Jews equaled cholera.

Awaiting what newspapers called the “cholera ships” were the Health Officer of the Port of New York, members of the New York City Board of Health and physicians from the Marine Hospital Service. As several inspectors in the port of New York noted, the ship’s log clearly stated that the drinking water loaded onto the boat for steerage passengers had been drawn directly from Hamburg’s Elbe River. By the time the ship docked in New York harbor, Hamburg officials had sent telegraphic notice to New York publicly admitting the Elbe River was contaminated with the bacteria that causes cholera. The sickened passengers hadn’t brought illness with them from home; they had become ill due to the contaminated water on the ship. German public health officials clearly exonerated the East European Jews as the cholera vector, declaring those they examined in Hamburg had been free from the disease when the ship departed.

With this information, local New York health officials wanted to give the steerage class passengers treatment, not to quarantine them. But Harrison decided to use this episode to achieve his goal of stopping immigration — an already existing nativist goal — and thus he ordered a 20-day quarantine to be paid for by the German shipping lines. He hoped to send a message to German shipping companies so that they would abandon the practice of offering steerage passage to groups likes Jews from Eastern Europe. He knew the price of quarantine was too high for them to bear.

In the end, Harrison’s quarantine executive order forced thousands of healthy people on steamships to be isolated on the islands in New York harbor. It also endorsed the harsh treatment of Russian Jewish immigrants who were ill and detained many prominent New Yorkers who had the misfortune of traveling in first-class cabins on the same boats as immigrants from Eastern Europe seeking better lives.

Harrison’s quarantine decree was not based in science but rather his desire to keep Russian Jews out of this country. The economic devastation was significant. For several months thereafter, the Hamburg-American line did not send ships to New York.

Harrison’s efforts to link Russian Jews to cholera promoted his nativist agenda, but did little good for public health in cities like New York. While cholera did not plague New York in 1892, it was because the city had heavily invested in one of the most advanced water filtration and supply systems erected in the Croton Aqueduct, which provided fresh, clean and cholera-free water for New Yorkers. This investment in infrastructure did more to protect public health than any quarantine.

Far from convincing German-shipping lines to abandon steerage passage, the 1892 quarantine taught Albert Ballin, the head of the Hamburg-American a critical lesson: good public health infrastructure is good businesses. He went on to build a whole network of checks to ensure the health of migrants traveling in steerage class. Investment in sound health-care infrastructure — whether they are water filtration systems or public health protocols — saves lives more than anything else.

Like Harrison, stoking xenophobia instead of shoring up our public health system is how Trump will be remembered during this historic moment in America. Rather than focusing on how to protect Americans from the virus’s destructive presence and capability, Trump deployed his trademark xenophobic language from the beginning to wrongly characterize the virus as “foreign or “Chinese,” ultimately encouraging the explosion of both anti-Chinese and anti-Semitic rhetoric. His followers and supporters followed suit, politicizing the virus calling the coronavirus as a “scam” fueled by enemies of Trump.

We need strong, central coordinated leadership in this moment of crisis to help health care providers get the medicine, equipment and personnel they need to save American lives. Ventilators, protective gear and other medical instruments should have been mass produced starting in February. Isolating the United States through the cessation of international travel should have been halted weeks before it was in March.

Though the president spent most of last week promising Americans will be able to fill the pews on Easter, before backtracking on Sunday, the worst thing Americans can do now is leave their homes, thereby preventing health care providers from addressing those in need. The Trump administration’s delays in reacting and misinformation have exacerbated the spread of covid-19. New York state was an early hotspot, but because New York state and city officials acted rapidly to close schools, create areas of containment and offer drive-through testing sites, areas like New Rochelle, the first cluster site, have seen a dramatic drop in new cases.

Let us recognize that by demonizing those fighting fearlessly in New York, New Jersey and Connecticut, Trump has downplayed states’ needs for more equipment and has suggested that to act, he requires governors’ gratitude. As the rate of U.S. infections skyrockets, he appears poised to cast blame on “blue” states and cities to gain favor with his base. As New York City’s inadequate medical infrastructure endeavors tirelessly to save as many lives as possible and conducts drug research that may help the rest of the nation combat this lethal virus, we must recognize the dangerous new chapter of Trump’s xenophobia: The idea of quarantining New York cast members of our own nation as a ‘foreign’ element infecting the nation. Let us not learn from Trump’s xenophobia but rather from the mistakes of President Benjamin Harrison over a century ago: supporting science not xenophobia will lead us through this crisis.