Francois de Fleury: the Most Badass Engineer of the American Revolution:

Hey, Army Engineer community, pull up a chair, we need to have a little chat about how we talk about our own history. Somehow, we always let the infantry, armor, and field artillery take center stage when it comes to talking about badass historical figures. We just sort of sit back and mutter, “Well, we built the roads you all use,” and get silently drunk in the corner. As usual. We’re like the Hufflepuffs of the Army, if Hufflepuffs were alcoholics with a severe predilection for explosives and heavy equipment. It’s almost as if we’re reluctant to get excited about our own profession. Suffice to say, we don’t talk about our own heroes enough. And oh boy, have we got a badass engineer to talk about today.

François-Louis Teissèdre de Fleury, born in 1749 in Provence, France. He arrives in America in March of 1777 with a contingent of other French Army officers. Congress wasn’t quite ready to give these foreign officers commissions, so de Fleury went ahead and entered Washington’s army as a volunteer. Two months later, he’s involved in a little dust-up in New Jersey where he distinguished himself enough that Congress relented and gave him a commission as captain of engineers on May 22.

By the fall of 1777, de Fleury is a major and serving in the Delaware river defenses around Philadelphia. Now, this is not a great time to be in the forts along the Delaware because British General Howe is intent on taking Philadelphia and is extending all his powers on land and water to do so. Washington keenly realized that Howe’s seizure of Philadelphia would mean little if he could not also control the Delaware River as a supply line, and ordered work begun on reinforcing Forts Mifflin and Mercer. De Fleury was ordered to Fort Mifflin on Mud Island in the Delaware, arriving on October 14.

What he found was not optimal. Fort Mifflin was an earth and timber fortification, more appropriate for a frontier defense than against a siege. It had been constructed back in 1771 by British engineer John Montresor – the man who now was directing the offensive against it. Montresor has an incredible story himself – he’d been literally everywhere in fighting in North America since 1754. He was wounded in Braddock’s disastrous defeat at the Monongahela, was with Wolfe at the taking of Quebec, mapped much of Quebec (including the route from Maine to Quebec later used by Benedict Arnold’s expedition in 1775), led troops during Pontiac’s Rebellion, was with Lord Percy’s relief expedition to Lexington in 1775, established landing sites for Howe at the Battle of Long Island, was witness to Nathan Hale’s execution, and was now besieging his own fort.

This fort now contained only about 500 men to man the batteries, fight off ground attacks, and repair damage to the fort. The British had already built several batteries that had the fort under fire, so he could only make limited improvements to already existing fortifications. In a detailed letter to Alexander Hamilton, de Fleury gave vent to all the things that he could have done to make the fort far more defensible, but one can imagine him shrugging in a “C’est la vie” way and carrying on with his duties. One day after his arrival, the British batteries opened fire, to little effect, he noted, causing “more Fear than Damage.”

Just to give you an idea of how chill this dude was, on October 16, he wrote to Washington that the shelling really wasn’t all that bad and hadn’t killed anyone – but that “the Bursting a shell just now drives me from my Table…” Yeah, to him, a British shell dropping through his roof was no big deal. During the nights, he supervised working parties to build additional protective works – ditches, berms, fighting positions – and also connected a chain across the river with Fort Mercer. This latter was done at night, in the water, under observation from the enemy, which had to have been absolutely terrifying and wretched for the men doing the labor. Enemy gunfire was incessant by October 23, but he noted on that day with some engineer happiness that fire from the fort had destroyed one British warship and caused another to go to ground.

But de Fleury was not blind to the dangers. He noted in a letter to Washington on October 28 that a determined storming party could seize the fort since it was so undermanned:

“You know this language is not dictated by Fear, but arises from a Sense of the importance of this Post. It is in vain to multiply works-of what avail are Fortifications undefended by Men.”

De Fleury to Washington, October 28, 1777
“The engineer author of this imperfect draught begg indulgence for it; considering that he has not paper, pen, rule, neither Circel, and being disturbed by good many shells, or cannon’s balls, flying in the fort.” Francois de Fleury, November 9, 1777. This is what we’d call a fighting product – a running estimate under fire. De Fleury was the best type of task force engineer. Source.

Joseph Plumb Martin, a member of the corps of sappers and miners, referred to the fort as nothing but a pile of mud. His journal recounts the misery of the siege: ” It was utterly impossible to lie down to get any rest or sleep on account of the mud, if the enemy’s shot would have suffered us to do so.” He also noted the zeal of the fort’s engineer. There was a rock ledge inside the fort that offered some scant protection, and men would gather there to escape the bombardment and try to warm themselves at a fire. When he noticed that the walls were looking a little slim on people, de Fleury would appear behind the ledge, brandishing a cane, “and woe betided him he could get a stroke at.”

In addition to fighting the enemy, the elements, and the exhaustion that plagued the fort’s small garrison, de Fleury also had to contend with the fort’s commanding officer, Lieutenant Colonel Samuel Smith. The infantry officer differed in opinion with this upstart engineer major, and so there were some disagreements. De Fleury noted these in his journal, in a way that many engineer officers will find familiar: “there are persons who know a great deal without having ever learnt-and whose obstinancy is equal to their Insufficiency.” Eventually, Washington had to write Smith to tell him, in essence, shut up and listen to your engineer:

His [Fleury’s] authority at the same time that it is subordinate to yours must be sufficient for putting into practice what his knowledge of Fortification points out as necessary for defending the post, and his Department, tho inferior, being of a distinct and separate nature requires that his orders should be in a great degree discretionary, and that he should be suffered to exercise his judgment…I place a confidence in him.”

By November, the Royal Navy had added their guns to the mix and were shelling the fort as well. The reason for this was that Howe’s army in Philadelphia was running low on supplies and Howe needed the Delaware open, no matter the cost. A Hessian land assault on Fort Mercer had been utterly crushed by the 1st Rhode Island Regiment – half of which was composed of African-Americans – and the Hessian colonel killed, so Howe was in a fine fury. On November 11, de Fleury noted that all the blockhouses had been blown to pieces and all guns in them dismounted save two. He himself was wounded during this timeframe but it does not seem to have caused him to lose his chill or his energy. Smith was wounded as well, and left the fort, so there was no one in command. This left Major de Fleury and Major Simeon Thayer to hold out as they could, even as Royal Navy vessels pulled so close to the fort that Marines could fire down into it and drop grenades from the crosstrees.

On November 15, Montresor directed his coup de grace. 24 guns from the land and 23 in Royal Navy floating batteries, assisted by the fire of larger warships in the main channel, opened up on the pile of mud called Fort Mifflin. At around 11 AM, while de Fleury was scrounging for more ammunition for the few guns left operational, Major Thayer gave the order to send up the distress signal on the fort’s flagpole. De Fleury and others persuaded him that doing so would show the British how weak they were, and to keep the flag flying until nightfall. The crazy engineer also somehow managed to get a 32-pounded and an 18-pounder back in action, mystifying the British who thought they had defeated the annoying pile of mud. Sometime in the late afternoon, a falling piece of timber knocked de Fleury senseless. With the crazy engineer out of the way, Thayer and the other officers agreed to evacuate the fort at nightfall with the flag still flying. Martin observed, as they evacuated, “The whole area of the fort was as completely ploughed as a field.”

Probably annoyed at having to give up his pile of mud, de Fleury recovered from his fight with a log. In 1778, he put forward a plan to engage the British fleet with fireboats, but it was never enacted. During the winter of 1778, the French engineer was detailed to assist Washington’s inspector general Baron von Steuben with the development of a drill manual for the Continental Army. Thus, an engineer had a hand in developing what was to become the U.S. Army’s first field manual.

Ok, so de Fleury was good at countermobility and survivability, two of the engineers’ core competencies. But what about mobility? Angry Staff Officer, you say, how can this guy be considered the most badass engineer of the Revolution if he never breached anything? Ah, dear reader, I’m glad you pointed this out. Because that brings us to 1779 and the Hudson River Valley. By this point in the war, the region was more or less static. Washington’s army glared at the British in New York City and British General Sir Henry Clinton glared back. In May, Clinton decided to do something to assert his dominance on the region. He sent troops up the Hudson and seized American positions at Stony Point on the west bank and Fort Lafayette on the east bank. Washington did not take the bait, and merely repositioned some forces to improve his defenses around West Point. Annoyed, Clinton withdrew most of his forces but left around 600 men garrisoning the forbidding height of Stony Point.

The heights of Stony Point – “the Table of the Hill” – inside the second layer of British defenses. De Fleury came up the slope on the right. (photo by author)

The British turned the small, rocky eminence into a “Gibraltar” of redoubts, entrenchments, and artillery batteries, protected by two lines of defensive obstacles composed of abatis – felled trees laced together, their branches sharpened into points. A causeway down the middle offered the only dry approach to the fort through swamps on either side. This was overwatched by three outposts with artillery. Royal Navy vessels added fire support from the river. Eff around and find out, the Brits were saying.

Well, if there was ever a guy to eff around and the finding out part be damned, it was General Anthony Wayne. Washington had given the Pennsylvanian command of the Continental Army’s Light Corps of 1779. These were picked troops from all the regiments of the Continental Line in Washington’s army, and had been trained to precision under von Steuben. Especially in the use of the bayonet. So it was to Wayne and his Corps that Washington turned in July to do something about this annoying British provocation. Oh, and did I mention that de Fleury was now with the Light Corps? Because of course he was.

Wayne and Washington developed a plan that would capitalize on surprise, initiative, and a crazy amount of courage. The assault would be made by the Light Corps – about 1,150 men – with a brigade of Continentals in reserve. The assault would occur at midnight, in three columns. One – 540 men – would advance in the north, taking advantage of a gap in the abatis that had been identified during reconnaissance. Another assault column of about 700 men would loop to the south, where intelligence had said the abatis did not fully extend into deep water (always, always, always integrate obstacles with terrain, people). A third column would attack on the main causeway in the center, opening a diversionary fire to fix the fort’s defenders. These would be the only attackers with loaded muskets; the rest would go in unloaded and with bayonets fixed. Each assault column would be lead by a pioneer party armed with axes to clear the obstacles. Naturally, de Fleury – now a lieutenant colonel – was in charge of the advance party behind the pioneers for the attack on the southern flank.

Map courtesy the U.S. Military Academy at West Point

On the very windy night of July 15/16, the troops got into position and advanced. The swamp was deeper than expected leading to a lot of silently cursing light infantry, but the columns pressed forward. British skirmishers opened fire, but their officers told them to knock it off, they were only firing at the wind. Suddenly, the diversion force in the center opened fire and the night was filled with the flash of musket muzzles and the roar of cannon. AS hoped, the fort’s reinforcements rushed to the center of the line.

De Fleury and his party hacked their way through the first abatis and then hit the second, situated on a steep slope where men were practically crawling to ascend it. De Fleury led the way through the breach of the second obstacle, Wayne nearby. Wayne was temporarily wounded at this point, leaving the engineer to lead the way. The Frenchman raced up the steep slopes toward the table of the hill, bayonets following him as the fighting swirled across the rocky slopes. Both assault columns had broken through, but it was de Fleury who first crossed the enemy’s main works – his third breach of the day – and hauled down the British flag, beginning the cry of ,”The fort’s our own!” from the Americans, the signal that the fort had been taken. At the cost of 16 dead and 83 wounded, the Light Corps had taken the fort and 543 British prisoners, with 19 British dead.

All told, as far as engagements go, Stony Point was a minor affair. But it did much to improve morale in the country in 1779 and it did quite a lot of Francois. As the first men into the works, he was awarded $500 from Washington and had a medal struck for him by Congress – one of the few medals awarded by Congress during the American Revolution. More on this, later. Francois de Fleury returned to France after the war and was appointed colonel of an infantry regiment in 1784. During the War of the First Coalition, he was wounded on the retreat from Mons in 1792 while trying to rally the rear guard. His wounds and health finally overtook him, and he retired later that year. We don’t exactly know when he died, but it was sometime before 1814. This badass engineer simply faded into history.

Back to that medal, though. The U.S. Army Engineer Association decided to name their highest award in honor of ol’ Francois. The De Fleury Medal is modeled off that given to its namesake by Congress.

The front of the medal has “A memorial and reward for courage and boldness” in Latin with an image of a soldier with a captured standard inside the fort. On the reverse, also in Latin, “Fortifications, marshes, enemies overcome,” which is sort of awesome, because it ties in to engineers shaping the battlefield. It’s an utterly badass medal, that comes in orders of steel, bronze, silver, and gold.

Which gets to my complaint: why the hell isn’t this guy always talked about? As engineers, we should be screaming his name from the hilltops that we build or capture. Even though we have an award named for him, most people have never even heard of why the award is named for him. As someone who embodies the engineer spirit, this should be a required story for every new engineer soldier and officer who passes through the humid and desolate gates of Fort Leonard Wood, home of the Engineer School.

So, this is my challenge to my fellow engineers: remember de Fleury! Remember our history! “The Fort’s our own!”


Cover Image: The Battle of Stony Point / J.H. Brightly, sc. Library of Congress.