Throughline - The Deadliest Ally | America in Pursuit

Episode Date: January 20, 2026

Forget guns and generals — the real victor of the Revolution had wings. This week on America in Pursuit the story of how a deadly swarm of mosquitoes shaped the American Revolution and changed the course of history.To access bonus episodes and listen to Throughline sponsor-free, subscribe to Throughline+ via Apple Podcasts or at plus.npr.org/throughline.Learn more about sponsor message choices: podcastchoices.com/adchoicesNPR Privacy Policy

Hey, it's run. In this month's Throughline Plus episode, our producers take us behind the scenes of making our episode on the first transatlantic cable. To listen to these insider bonus episodes every month, sign up for ThruLineplus at plus.npr.org slash throughline. This is America in Pursuit, a limited run series from ThruLine and NPR.

I'm Ramtin Arablui. Each week, we bring you stories about life, liberty and the pursuit of happiness in America that began 250 years ago this year when those rights, unalienable rights, were laid out in the Declaration of Independence. But Americans had to fight for them, beginning, of course, with an all-out revolutionary war that lasted years. So for our first episode, we're going to go back into the archives to bring you a story from that revolutionary fight, which you probably know the basics of.

People were mad about taxes and were tired of answering to a king. The Boston Tea Party broke out, George Washington and his crew took up arms and defeated the Imperial British Army with unconventional tactics. But there's a big, or should I say small, part of this story that's rarely mentioned. Mosquitoes. It's still the animal that kills more human beings on the planet than any other animal to this day, and that's including other humans. That's Dr. Tim Weingard. I'm a history professor at Colorado Mason University, also the head coach of the hockey team being Canadian,

and I wrote the book, The Mosquito, A Human History of Our Deadliest Predator. The specific mosquito we're talking about today is known as the Anopheles, a species of mosquito that thrives in marshes and swamps, and is known for spreading malaria, a deadly disease that has changed the course of history in all kinds of ways. We like to think we get to make our own history, that we did this as human beings. And that's not necessarily the case. We head to the battlefield with the Annapolis Mosquito when we come back.

It's 1778, three years into the American Revolutionary War. The first half of the war was fought almost entirely in the north. George Washington and the Continental Army were having mixed success and spent a lot of energy running from the British Army. trying to buy more time. The British are very upset that General Washington won't essentially commit to a decisive battle to end the war.

And Washington knows he can't do this because he doesn't have anything. If he commits to a decisive battle and loses, the revolution's over. But as long as he can keep an army, however ill-supplied and under-equipped in the field, the British have to defeat and chase this army. All the while, he's desperately waiting for help to come.

He waits for his political, lords essentially in the Continental Congress to get some supplies, get some allies, get some weapons, and hopefully get France on board. This is essentially playing cat and mouse, and it frustrates the British. So they changed their strategy. The British concentrated their forces in the southern colonies of Georgia, South Carolina, North Carolina, and Virginia. Second in command of this campaign was General Charles Cornwallis, who landed in Charleston with nine thousand British soldiers. And these soldiers come primarily from northern England and Scotland, these British soldiers.

So there was malaria in England, but these soldiers specifically are recruited from Northern England and Scotland away from the Malarial Fenlands of England. So they're not what is called seasoned. What seasoning is essentially the more you suffer, the less you suffer. Now, I don't suggest this as an inoculation. strategy, but generally speaking, the more you can track malaria, the less severe the symptoms are and the less likelihood of dying. So the American soldiers have been seasoned to their colonial malaria.

They've had malaria. They've been seasoned to it. Where these British soldiers come over, they haven't been seasoned to their own English malaria, let alone colonial stew of malaria. And this new set of circumstances in the South forced Cornwallis to adopt someone unusual tactics. If you look at his campaign in the South in 1780, 1781, he is zigzagging all over the place. It is one of the strangest marches you've ever seen on a map.

And so why is Cornwall doing this? Is he running away from the Americans? Is he chasing the Americans? No, he's trying to find a healthy spot for his troops. With a third of my army sick and wounded, which I was obliged to carry in wagons or on horseback, the remainder without shoes and worn down with fatigue. I thought it was time to look for some place of rest and refitment. And he says this repeatedly in his correspondence is he says that malaria is ruining my army

and he's asking British loyalists in the southern colonies where there's a healthy spot and because they're seasoned they say, oh, just go that way. And then he gets there and his troops are cut to pieces by malaria again. I am now employed in disposing of the sick and wounded, and in procuring supplies of all kinds to put the troops into a proper state to take the field. I am, likewise, impatiently looking out for the expected reinforcement from Europe, to enable me either to act offensively or even to maintain myself in the upper parts of the country. Where alone I can hope to reserve the troops from the fatal sickness, which so nearly is. ruined the army last autumn. April 10th, 1781.

As Cornwallis was running around looking for a safe, mosquito-free spot for his troops, he got an order from his superiors to retreat and fortify at the port of Yorktown in Virginia. Yorktown is a little hamlet situated in the tidewater estuaries between the James and York rivers. Essentially, it's rice paddies, it's marshland. So he holds up in Yorktown. French Navy comes, they're eventually joined by General Washington and the Americans, and they ensnare the British in Yorktown.

This is in August, which is prime mosquito time in prime mosquito country in these marshlands surrounding Yorktown. His army was decimated, and in October, General Cornwallis surrendered. I have the mortification to inform your excellency that I have been forced to give give up the post, and to surrender the troops under my command. The troops being much weakened by sickness, as well as by the fire of the besiegers. In his correspondences, Cornwallis lay some of the blame for his surrender on malaria. Our numbers had been diminished by the enemy's fire, but particularly by sickness. He's like, I don't have anybody who can even stand up to fight.

He only has 35% of his troops, roughly, who are able to even stand up. Our force diminished daily by sickness to little more than 3,200 rank and file fit for duty. The rest are either sick, dead, or dying of malaria. The siege of Yorktown was the final battle in the war between the colonies and Great Britain, opening the path for the formation of the United States. So in a way, Dianofli's mesquist, The mosquito is the founding mother of the United States, and she deserves to have her nice proboscis face tucked in between Washington and Jefferson on Mount Rushmore.

Our founding mother, the mosquito, looms large over the history of humanity. And as Tim told us, her reign is not limited to our past. She may completely transform our future. Human beings are crisscrossing the planet for trade, travel business at record rates to record numbers of destinations in record numbers everywhere. Disease is a constant baggage to human migration. Whether that be war, trade, travel, it doesn't matter. It's a universal creature and has been forever, essentially.

Her reach and her historical impact and influence kind of cross both time and space. Time is kind of irrelevant to her reach because at every stage, the mosquito and these pathogens have essentially been able to circumvent our frontline weapons to continue what they're pre-wired to do, and that's simply reproduced. So we are constantly trying new and innovative techniques to break this eternal stalemate that we've had with our deadliest enemy and deadliest predator. That's it for this week's episode of America in Pursuit, a special series from ThruLine and NPR. If you want to learn more about the role mosquitoes have played in shaping history,

check out ThuLine's full-length episode called Buzzkill. And make sure to join us next Tuesday when the American Revolutionaries tried to figure out how to build a new nation and a new government, relying a lot on something you probably wouldn't expect, the post office. It was the nervous system of the republic. That's next time. Don't miss it.