The Fourth Horseman


By Robert Koenig

Formats and Prices




$19.99 CAD




ebook $14.99 $19.99 CAD

This item is a preorder. Your payment method will be charged immediately, and the product is expected to ship on or around April 29, 2009. This date is subject to change due to shipping delays beyond our control.

The story of Anton Dilger brings to life a missing chapter in U.S. history and shows, dramatically, that the Great European War was in fact being fought on the home front years before we formally joined it. The doctor who grew anthrax and other bacteria in that rented house was an American — the son of a Medal of Honor winner who fought at Gettysburg — on a secret mission, for the German Army in 1915. The Fourth Horseman tells the startling story of that mission led by a brilliant but conflicted surgeon who became one of Germany’s most daring spies and saboteurs during World War I and who not only pioneered biowarfare in his native land but also lead a last-ditch German effort to goad Mexico into invading the United States. It is a story of mysterious missions, divided loyalties, and a new and terrible kind of warfare that emerged as America — in spite of fierce dissention at home — was making the decision to send its Doughboys to the Great War in Europe.

This story has never been told before in full. And Dilger is a fascinating analog for our own troubled times. Having thrown off the tethers of obligation to family and country, he became a very dangerous man indeed: A spy, a saboteur, and a zealot to a degree that may have so embarrassed the German High Command that, after the war, they ordered his death rather than admit that he worked for them.




One Man’s Secret Mission to Wage
the Great War in America


For Mary Ellen, Laura, Mark, Chris, and Claire

When he broke the fourth seal . . . another horse appeared, deathly pale, and its rider was called Plague, and Hades followed at its heels.



Germany, November 1918. Two million of the nation’s sons had perished in a lost cause. An empire had collapsed, causing social, political and economic upheaval. And a deadly plague, in the form of the Spanish Flu, had struck like a diabolical retribution.

When the knock came at the door of Eda Koehler’s house in Mannheim, she stood there for a moment, frozen in the entryway, afraid to confront yet more terrible news. The war had been a disaster for her family, but all was not yet lost. Her despondent husband’s business had been ruined, but they still had their house. And their son had survived, miraculously, four years as a cavalryman.

Steeling herself for a new disaster, she slowly opened the door and peered through the crack. It was a military courier carrying a package. He asked to be admitted and, once in the hallway, explained that the box contained possessions that had been found in her brother’s apartment in Madrid. Germany’s military attaché there had listed her as the next of kin.

She paid the courier a small tip—she had little to offer—and carried the package to the dining room table, where she unwrapped it. Anton had been her favorite brother and, in a sense, her son. She had taken him from the family’s farm in Virginia and reared him in Mannheim since he was ten years old. She and her husband had paid his way through Germany’s best medical school. They had been proud when he became a surgeon and served his adopted country. But then her little brother, her “son” and confidante, had disappeared into the half-light of rumored subversion and espionage.

Inside the box was a battered suitcase; she undid the clasps and removed its contents. Tears came to her eyes when Eda saw a bloodied white shirt inside. The cut was stylish, the sort of shirt that Anton would have worn. It had been carefully folded, even though no one could ever use it again. Why, she wondered, would the front of his shirt have been covered with blood? They told her that Anton had died of pneumonia.

She unfolded the shirt and examined the parts of the fabric that had not been stained with blood. In a rare moment of candor, Anton had once told her that he would use invisible ink to write secret messages on shirts. If customs officers searched his suitcase at borders, he had boasted, they would sometimes examine papers and books—but would never look at the dirty laundry.

The next object in the suitcase was a set of golden cufflinks bearing the seal of the King of Bulgaria. These Eda recognized as her brother’s, for she had seen him wear the cufflinks at dinner parties in Mannheim when he bragged about how the King, who had a predilection for handsome young men, had given him the golden keepsakes.

Wedged into the corner of the suitcase was a book, written in English, that she had never seen before: My Four Years in Germany. The author was the former American ambassador, James Gerard, who had harshly criticized Imperial Germany. Her brother, an American who had become a German, would have despised the book. It was incongruous with the small collection of otherwise personal items.

When she looked closer, Eda saw that there was a secret pouch in the front cover of the book, a place where someone could hide a message or a photographic negative. Written in Spanish was an inscription to Anton, signed “Roberto Wilson.” “Dedicated to my dear friend on his birthday, with the hope that this book will change his Germanophile outlook.” Wilson, she learned much later, was the false name of a German spy.

There were more wrapped objects in the suitcase, but Eda did not want to explore them all at once. Her brother had meant too much to her; she wanted some time to think about what he had left behind. She boiled some water and made herself a cup of what passed for tea those days in rationed Germany, walked up the stairs to her bedroom and searched for the letter that her sister, Elizabeth, had sent to her the previous month, after hearing of Anton’s sudden and mysterious death.

“I was devastated when I heard the terrible news last night,” Elizabeth had written. She had been startled because a friend had sent a recent message from Madrid, saying that Anton—a civilian doctor, after all, and not a military man—had been in good health. “For those of us who remain behind, it is a constant hurt, a bitter wound—one wonders if one can continue to bear the burden of the cross.”

Eda realized that her sister had only one cross in mind—that of the crucified Christ—but the letter made her curious about something else among her brother’s possessions. Returning to the suitcase, she pulled out a few more articles of clothing and then saw a small black case—about the size of a cigarette case—hidden underneath. She knew what she would find inside as she opened the case because her son the cavalryman had been awarded the same decoration: the Iron Cross.

The simple ribbon was black with two white stripes. The medal itself was a stylized cross of black with a silver border. Stamped on the black surface was the image of the crown and a W for Kaiser Wilhelm II—the emperor who just weeks earlier had abdicated and fled to a safe haven in Holland. At the foot of the cross was stamped that year, 1918. Confused but intrigued, Eda rubbed her thumb over that date.

Years before, when she was a young woman still living in westernVirginia, her father had been so proud to show off his Medal of Honor—America’s highest military award. He had been born a German but had become a loyal American.

Under what circumstances had the Medal of Honor winner’s son received a military honor—not from America, the land of his birth, but from its implacable enemy? What tragic chain of events, wondered Eda, had ended with the bloody shirt and determined the fate of the man whose meager personal possessions she now owned, her brother Anton Dilger?

part one


Chapter 1


Take the [Germans] out of the Union Army and we could whip the Yankees easily.

Attributed to ROBERT E. LEE , 1863

ANIMALS WERE FLEEING THE FOREST. Frightened rabbits, deer, and foxes snapped branches and rustled through the dry brush as they ran across the clearing in front of Captain Hubert Dilger’s mount. Spooked by the wild-eyed terror in the animals’ eyes, the horse moved nervously under the captain’s tight rein. Something was moving through the woods; Dilger suspected an enemy assault.

Riding closer to the forest’s edge, he heard a gunshot and then the sudden, terrifying sound of a hundred Rebel yells. The surprise attack on the Union Army had begun. Dilger’s horse artillery battery moved into action, firing double-shotted canister—a lethal spray of shrapnel—at the Confederate soldiers who rushed toward his guns from deep within the woods. His men fought to delay the advance enough for their division commander, General Carl Schurz, to swing his troops around and confront the attack.

“Within little more than rifleshot of our right flank there stood ‘Stonewall’ Jackson with more than 25,000 men, the most dashing general of the Confederacy with its best soldiers, forming his line of battle which at the given word was to fold its wings around our feeble flank,” Schurz wrote later. Lined up against the Rebels were the 9,000 Union troops of the 11th Corps, most of them stunned by the surprise assault.

“Stonewall” Jackson, riding his sure-footed horse Little Sorrel, had driven his men all night through the forest near Chancellorsville, Virginia, to attack the Union Army’s exposed right flank. With fierce yells and frightening volleys of musket fire, the Confederate soldiers charged from the woods near the Wilderness Church, where Schurz had positioned the German-speaking regiments that now bore the brunt of the Gray onslaught. Wrote one chronicler of the battle: “So rapid was the advance, so utterly unexpected the attack, that the pickets were at once over-run; and . . . the broad front of the mighty torrent bore down” upon the Germans.

Hubert Dilger—known to his troops as “Leatherbreeches” because of his doeskin pants—and his gunners were soon outflanked and attacked by an overwhelming force. With the Rebels firing at ever-closer range from the thickets, Dilger ordered his unit to continue firing canister to cover the withdrawal. They had to fall back, but Confederate sharpshooters began to pick off the horses that pulled one of the guns.

Suddenly a sniper’s shot rang out and Dilger felt his own horse shudder beneath him. The wounded animal wheezed in pain as it fell, hitting the ground and pinning the celebrated Leatherbreeches under its dead weight. Blood oozed from the wounds as Dilger struggled to extricate himself. The Rebels were moving closer, firing at him and his men, and calling for Dilger to surrender.

Just as it seemed that the captain might be consumed by the carnage around him, a local boy named Ackley attempted a heroic rescue. He had seen the gallant captain lead his battery toward the front and then the boy realized that the captain was missing during the unit’s retreat. “Seizing a horse, [the boy] rode directly into the front of the enemy in search of him,” according to one account. Through the haze of gun smoke, Dilger spotted the stallion led by the boy. The captain freed himself from the dead horse, mounted the fresh one with the boy, and dodged Rebel bullets as they galloped back towards the Union lines.

As dusk fell, the Rebels reorganized and struck again at the Union rear guard—now down to Dilger and his cannon—withdrawing slowly toward Chancellorsville. Because the road was so narrow, Leather-breeches could use only one gun. He had sent the others back to join a different artillery unit but then stubbornly held his ground. “Dilger himself stayed with his one gun, firing it like a pocket pistol—a couple of shots down the road, limber up and go back a hundred yards, unlimber again and fire some more; one man and one gun, standing off the advance of Stonewall Jackson.”

One brave man’s heroism did not sway the Battle of Chancellorsville. In the end, the Rebels claimed the victory, won by the brilliant strategy of General Robert E. Lee and the surprise tactics of Stonewall Jackson. It was May 1863, and the Confederates were nearing the apogee of their territorial strength. The Rebel cavalry still ranged through the Shenandoah Valley and across large swaths of Maryland. Meanwhile, the Union Army had suffered a string of defeats, and its soldiers—many of them Irish or German immigrants—were demoralized.

The night of his rear-guard heroism, an exhausted Dilger watched an artillery barrage so intense that it set the woods afire; he could hear the screams of wounded soldiers being consumed by the flames. Years later, in The Red Badge of Courage, Stephen Crane would attempt to convey the deadly artillery barrages at Chancellorsville:

On a slope to the left there was a long row of guns, gruff and maddened, denouncing the enemy, who, down through the woods, were forming for another attack in the pitiless monotony of conflicts. The round red discharges from the guns made a crimson flare and a high, thick smoke . . . A congregation of horses, tied to a long railing, were tugging frenziedly at their bridles.

That night, Stonewall Jackson rode his warhorse to the battlefield’s fringe to scout ways of cutting off the retreating Union soldiers. As dusk fell, Jackson and his entourage of staff officers returned, but a Rebel unit mistook them for the enemy in the dark woods and fired a volley. Little Sorrel turned away from the gunfire, but too late to prevent three bullets from striking Jackson in the right hand and left arm.

When Jackson’s stricken hand dropped the reins, his terrified horse ran into the woods toward the Union lines. A tree bough struck Jackson’s head, but the general managed to hold on to the horse, grab the bridle with his bleeding hand and turn Little Sorrel toward the road, where a Rebel captain caught the reins. When the horse finally stopped, the mortally wounded Jackson slid forward into the captain’s arms.

Stunned soldiers carried the general away on a stretcher as Little Sorrel watched, riderless. It was the last time the horse—which had been Jackson’s trusted mount on nearly every campaign since Bull Run—would see his master. Doctors amputated Jackson’s arm later that day; the fever-stricken general died within a week. Little Sorrel would live for another two decades, idolized throughout the South as a surrogate for its late master.

With Jackson gravely wounded, General Lee had precious little time to savor the victory at Chancellorsville. A few weeks later, the tide would begin to turn with Union victories at Gettysburg and elsewhere. The Union cavalry, which had performed poorly during the war’s first two years, had begun its resurgence at Chancellorsville, and Lee’s own forces already were feeling the pinch of tight supplies.

The day after the battle ended at Chancellorsville, General Lee rode his iron-gray horse, Traveler, across the abandoned battlefields. An old-school horseman, Lee personified the chivalry and gallantry that the brutal war lacked. Traveler, the mount Lee praised for its “sagacity and affection and his invariable response to every wish of the rider,” would become perhaps the most famous warhorse in American history.

The victory may have seemed hollow to Lee. The battlefield was scarred by cannonball-shattered tree trunks and wide sections of woods and scrub that had been blackened by fire. Thousands of soldiers’ corpses had been hauled away for burial. The bodies of dead horses—bloated, bloody, with flies buzzing around them—still littered the war zone.

What had been won, in the end? More dead men, more dead horses, a few square miles of territory destroyed and conquered. This could not go on forever.

With a pull on the reins, Lee urged Traveler onward, away from Chancellorsville and toward the next battlefield. Always faithful, the warhorse obliged.

“LET YOUR HEADQUARTERS be in the saddle,” General Ulysses S. Grant had advised one of his Union commanders in 1864. Indeed, horses played a crucial role in the Civil War.

Less than a month before the Chancellorsville battle, President Abraham Lincoln had traveled to northern Virginia to review the Union cavalry, riding a steamer down the Potomac River to Aquia Creek, then riding horses or carriages to inspect the troops.

The tall and gangly Lincoln rode a short bay horse while Union Army Commander General Joseph Hooker rode a stunning white stallion to the reviewing stand. They were joined by General Schurz, a German-born political ally of the President, in reviewing the newly reorganized Union cavalry. It took an hour and a half for the columns of cavalry and artillery, including Hubert Dilger’s unit, to march past the reviewing stand.

The long line of warhorses that Lincoln had inspected in 1863 represented a major reason why the Union would emerge victorious. Both sides were losing horses and mules by the hundreds of thousands, through battlefield injuries as well as exposure, starvation, and disease.

The North had begun the war with an advantage in horsepower, about 3.4 million horses and 100,000 mules, compared to 1.7 million horses and 800,000 mules in the South. But Union Army leaders had been slow to recognize the need for a mounted force, while Confederate generals moved quickly to organize their mounted units.

By the time of the Chancellorsville battle, however, the Union cavalry was maturing and the Confederate cavalry declining, hurt by shortages of both horses and mounted soldiers. General Hooker had ordered that a Cavalry Corps be formed from various mounted units that had been scattered through different Army commands. He also set up a Cavalry Bureau, charged with organizing and equipping the cavalry forces with horses, weapons, saddles, and other essential supplies.

Later, Union General Philip H. Sheridan began using his cavalry units independently against Confederate cavalry and infantry, rather than limiting them to guarding wagon trains or serving as advance guards for infantry columns. In the end, the North’s new tactics and its advantage in horse resources proved decisive.

But the losses on both sides were devastating: in 1863, the Union Army needed about 500 new horses per day to replenish its losses; 1.5 million horses perished by the war’s end. Many died from exhaustion or were killed outright by enemy fire, the targets of enemy sharpshooters on both sides. Aside from bullets and shrapnel, the worst enemy of horses was disease and exposure to horrible conditions. A horse disease called glanders struck with a vengeance during the war, when tens of thousands of horses—some have estimated 200,000—perished from the dreaded and incurable disease in Union and Confederate stables. It was the worst glanders outbreak in American history.

Some officers suspected that one side or another had deliberately left behind horses with glanders in an effort to infect the enemy’s horses. After the Battle of Bull Run, Union Colonel Samuel Ringwald told the commanding general that when the Confederates abandoned the Virginia battlefield they had “carefully left behind . . . a number of horses infected with that horrible and contagious disease, the glanders.”

Farther south, in the Rebel stronghold of Lynchburg, Virginia, glanders spread like wildfire at stables where the Confederates quartered thousands of horses and mules. The disease killed an estimated 3,000 animals in the depot over 15 months in 1863–64. The animal epidemic was so bad that two Virginia physicians were asked to investigate the “baneful scourge” of glanders in the horse depot. Their research, published in an 1864 pamphlet, is regarded as the first important American contribution to veterinary medicine.

After the war, when the horses and mules that were left in Union military depots were put up for sale, some buyers accused the government of selling glandered animals and spreading the outbreak. The American Agriculturalist magazine opined: “The Government might better have shot every horse, than to have them spread contagion and death (for the disease is utterly incurable) among the stables of the country, far and near.” A half century later, that editorial seemed prophetic.

THE GIRL’S DELICATE HANDS trembled when she first made contact. In the darkened Philadelphia parlor, she sensed the presence of a sad-eyed man, a leader who had been struck down by an assassin’s bullet at the time of his greatest glory.

Her pen, which she insisted was guided by a force that moved her pliant fingers, slowly wrote out the leader’s “spirit messages” on a sheet of paper. The girl’s older sister, Elise Tiedemann, read the first words aloud to the guests around the séance table:

I am present
The dinner guests—some enthralled, others merely feigning interest—murmured to one another in German amid the parlor’s old-world furnishings. The spirit the girl claimed to be present was that of the President who had been murdered at Ford’s Theater in Washington a few months earlier: Abraham Lincoln.

The guest of honor at that evening’s séance was Carl Schurz, who was a political supporter of the late President, a Civil War general, and perhaps the most influential German American of his time. Half-jokingly, the bearded Schurz suggested to the girl: “Ask him if he knows why President Johnson has called me to Washington.”

A few of the guests laughed or cleared their throats; others leaned forward to hear the supposed spirit’s response. The girl—Charlotte, a fourteen-year-old with an angelic face—trembled as she slowly wrote out a message that Elise, sixteen, read aloud:

He would like you to make an important journey for him.

Amused but intrigued, Schurz—an intense man who wore wire-rimmed spectacles on a cord that clipped to the lapel of his long black dinner jacket—asked, again half-jokingly, if Lincoln’s spirit had any more to tell him. After a long pause, Charlotte wrote:

Yes, you will become a U.S. senator.

Some at the séance table smiled. “This seemed to me so fantastic that I could scarcely restrain my laughter,” Schurz recalled later. “I asked further, ‘From what state?’” The spirit’s response: Missouri. Schurz laughed aloud this time. “Nothing . . . was more unlikely than my becoming a senator from Missouri,” he remembered. “My legal residence was Wisconsin and it was my earnest intention to return there.”

Séance pronouncements that don’t materialize tend to be forgotten. But those two predictions made by the young spirit-writers eventually came true. When Schurz met with the president at the White House later that week in 1866, Johnson sent him on a fact-finding mission to the South. Two years later, Schurz became a U.S. senator from Missouri, the first German American in the Senate. In his memoirs, written forty years later, Schurz—a rationalist who normally had little patience for the occult—praised the Tiedemann family’s “circle of spiritualists.”

Some in society regarded the spirit-writers Elise and Charlotte as more flatterers than occultists. They were daughters of Dr. Heinrich Tiedemann, a prominent physician, and his well-connected wife, Charlotte (née Hecker). In the years after the Civil War, the family hosted a parade of prominent German Americans at their home in the aptly named Germantown district of Philadelphia. They were among about six thousand German political refugees, known as “’48ers,” who had fled the Old World after the failed democratic revolution of 1848–49 to form the core of a new German American intellectual and political elite. During the ’48er insurrection, southwestern German reformers had taken up the banner of French revolutionaries to seek social and political changes, including the establishment of republics in what had long been kingdoms.

The Tiedemanns’ revolutionary credentials were impeccable. Mrs. Tiedmann’s brother, Frederich Hecker, was a lawyer whose fiery rhetoric had helped spark the Social Democrat uprising. Hecker was also widely rumored to have been an illegitimate son of Bavaria’s King Maxi-milian I. Arguing for a new, democratic state that would distribute wealth and offer equal opportunities, Hecker had traveled widely through Baden, where years of poor harvests, unusually cold winters, and devastating floods had spread hunger and unrest. When the ’48er revolution failed, Hecker had fled Germany and settled as a “Latin Farmer”—a highly educated agriculturalist—in southern Illinois.


On Sale
Apr 29, 2009
Page Count
304 pages

Robert Koenig

About the Author

Robert L. Koenig, a Contributing Correspondent for Science magazine, has written about German topics for more than two decades, covering stories ranging from the fall of the Berlin Wall to revelations of atrocities in Nazi-era scientific research. He also conducted archival research into the history of germ warfare during his three years as publications director of a leading microbiology research laboratory near Washington. D.C.

Learn more about this author