It has been 100 years since the first act of terror on U.S. soil was committed by revolutionary Francisco “Pancho” Villa. On March 9, 1916, Villa and more than 400 heavily-armed mounted bandits crossed the Mexican border and attacked Columbus, New Mexico. The Villistas caught the town of 350 inhabitants, plus a garrison of 553 troops from the 13th U.S. Cavalry, completely by surprise. “I was awake, they were asleep,” he later bragged, “and it took them too long to wake up.”

For almost two hours Villa’s men ransacked the town’s hotel, its few stores, and adobe houses before the cavalry chased them back across the border. Left behind on Columbus’s dusty streets lay eight dead civilians and 10 American soldiers, and several others wounded. The Villistas took greater losses, between one and two hundred men, some killed during a cavalry skirmish 30 miles deep into Mexico.

Villa’s raid was an act of terrorism and the first of its kind conducted on U.S. soil. Unprovoked, his men gunned down innocent Americans and destroyed their property. Although the death toll pales in comparison with the 9/11 attacks or the recent Paris mass shootings, the American public was stunned and demanded immediate retribution, fearing Villa was on a rampage with plans to massacre other border towns. President Woodrow Wilson, a reluctant warrior, was in the midst of a re-election campaign that pledged to keep America out of the war in Europe. A war with Mexico was now a possibility and he had to act.

Villa never said why he orchestrated the attack, but his hatred for America was no secret. He was angered that the Wilson administration formally backed Villa’s chief political rival, Governor Venustiano Carranza. Seeking revenge three months before the Columbus raid, his Villistas murdered 18 Americans on board a Mexico train. Wilson ignored the episode and did nothing.

Yet, a day after Columbus was hit, Wilson needed to look strong and ordered his new secretary of war, Newton D. Baker, to send an armed force into Mexico. A week later, a punitive expedition of more than 14,000 troops under the command of Brig. Gen. John J. Pershing, including aide Lt. George S. Patton, headed to Mexico in pursuit of Villa.

Today, Pancho Villa is more associated with a slew of Mexican restaurants that bear his name than his true legacy as a cold-blooded killer. Villa was not a folk hero as some would like to believe, but a violent terrorist whose actions remind us of the atrocities committed by ISIS a century later.

—Mitchell Yockelson

Excerpted from Forty-Seven Days: How Pershing’s Warriors Came of Age to Defeat the German Army in World War I by Mitchell Yockelson:

Pancho Villa and around four hundred men raided Columbus, New Mexico, on March 9, 1916, and tangled with the 13th U.S. Cavalry Regiment, who were garrisoned nearby. Villa supporters had been terrorizing Americans in Mexico and conducting border raids for the past year in retaliation for the U.S. backing of President Venustiano Carranza, with whom Villa was embroiled in a civil war. The day after Villa’s invasion, President Wilson “directed that an armed force be sent into Mexico with the sole purpose of capturing Villa and preventing any further raids by his band, and with scrupulous regard to the sovereignty of Mexico.”

Secretary of War Baker, who had just arrived in Washington and knew little about the Army’s field officers, asked his general staff to recommend an expedition leader. Army chief of staff Major General Hugh L. Scott and his assistant, Major General Tasker H. Bliss, put Pershing’s name forward, and Baker selected him. The other possibility was Major General Frederick Funston, a Medal of Honor recipient and commander of the Southern Department out of Fort Sam Houston in San Antonio. Funston outranked Pershing and seemed the obvious choice, but reports that he drank too much ruined his chances. Pershing also had more experience working directly with civilians than any other officer, and that comforted Baker.

Out of all his Army assignments, commanding the Mexican Punitive Expedition was the most difficult. Capturing Villa would be hard enough, considering the bandit knew the terrain better than Pershing and had many allies willing to protect him, but entering Mexico and not inciting its army into a full-scale war would be another challenge. Just after midnight on March 18, 1916, Pershing and the Mexican Punitive Expedition brought the U.S. Army into the modern era of warfare. Accompanying the 12,000 Regulars were motorized supply trucks, Signal Corps communication equipment, and some airplanes. Pershing split his army into two columns and headed toward the town of Casa Grandes, 100 miles south of Columbus. A supply base was established at Colonia Dublán and this is where Pershing made his headquarters.

Four weeks into the operation, Pershing’s Punitive Expedition had pushed 350 miles into Mexico without snagging Villa, although there had been several skirmishes with his Villistas. On March 29, 1916, 370 troopers from the 7th Cavalry Regiment clashed with Villa’s bandits at San Geronimo ranch near the town of Guerrero. Seventy-five Villistas were killed and five Americans wounded. Villa escaped unharmed; it was the closest Pershing’s men would get to capturing him. On April 12, a squadron of the 13th Cavalry entered the town of Parral, 400 miles from the border, where they were swarmed by an angry crowd. Wisely, squadron commander Major Frank Tompkins tried to leave town and was attacked in the process by the local Carranzistas (the name given to Carranza’s military forces). Tompkins engaged the Mexicans, and after more American cavalry arrived throughout the day, the outnumbered Carranzistas withdrew. Two Americans died and six were wounded during the standoff. There were many more Mexican casualties, although the exact number is disputed.

Frustrated by failing to locate Villa’s whereabouts and fighting Mexican troops in the process, Pershing’s men grew tired and aggravated. Cavalry regiments were overly exhausted because much of the landscape they traversed was mountainous and troopers often had to lead the horses on foot. Mexican villagers added to the misery. Pershing ordered his men to treat them with respect and purchase their goods at fair prices, as he had done with the Moros. But locals didn’t reciprocate the kindness and snubbed the Americans when asked for help finding Villa. Even more distressing was the Carranza government, which had reluctantly permitted the expedition into Mexican territory under pressure from Wilson but now hoped the Americans would go away.

Pershing thought the 1st Aero Squadron, with its eight Curtiss JN-3 (Jennys) airplanes, led by Captain Benjamin Foulois, could help spot the bandit. He was mistaken. One of the planes crashed on its maiden flight from Columbus to Colonia Dublán, and the other planes either couldn’t fly much above the treetops, or suffered from broken propellers, among other failures. Pershing lamented that the “aeroplanes have been of no material benefit… either in scouting or as a means of communication. They have not at all met my expectations.”

On June 21, the last major battle of the expedition involved Pershing’s old regiment, the 10th Cavalry. Once again the enemy was not the Villistas but the Mexican Army. Eleven American soldiers were killed in a skirmish at Carrizal, including the commander of Troop C, Captain Charles Boyd, when the regiment entered the village without approval from the local Carranzista commander. Pershing wanted to retaliate by attacking the Carranzista garrison at Chihuahua, but President Wilson rejected his order for fear it would lead to war between the United States and Mexico and requested that the commander now cease hostile activity. Pershing obeyed and agreed that he would stand down until further notice. Despite the lack of progress and frustrations over equipment failures, Pershing kept his composure and remained professional throughout the expedition. This is apparent in one of the iconic photographs taken of him at the time. Pershing is captured sitting confidently on his horse. A “Montana Peak” campaign hat rests just above his ears, while he wears a crisp shirt and perfectly knotted tie.

Patton saw his first combat during the Punitive Expedition. For the first couple of months he served under Pershing’s watchful eye as his aide. Patton tended to scheduling, ordering supplies, and any other administrative task he was told to do. All the while he observed Pershing’s command style, and wanted so badly to emulate him. As one of Patton’s biographers put it, “Pershing’s influence on young Patton cannot be overemphasized. He was the very model of a military commander, whose ideas of duty and discipline meshed perfectly with Patton’s own conception.” Pershing, too, appreciated the young lieutenant for his energy, ambition, and hunger for action that reminded Black Jack of himself when he had first started out. He brought Patton along during morning horseback rides, and they slowly developed a strong bond. Pershing saw that Patton longed for adventure, and occasionally sent him out in the field as a courier. Besides these small excursions, however, Patton remained at headquarters, helping his boss to keep the expedition organized.

After weeks of little movement, and with Villa and his band still on the loose, Pershing received a credible tip in early May 1916 that General Julio Cárdenas, Villa’s trusted bodyguard, was holed up in the vicinity of Rubio. Capturing Cárdenas would be a major coup for Pershing, and Patton wanted to take part in the score. Patton made his pitch; Pershing bought it and temporarily assigned his aide to Troop C of the 13th Cavalry. At daybreak one morning the regiment went looking for Cárdenas. They searched the San Miquelito Ranch, where the Cárdenas family was supposedly living, but only an uncle and some other relative were home. From there the troop scoured the surrounding countryside, but came up empty-handed. Patton was disappointed and vowed to return to the ranch.

His chance came a couple of weeks later when Pershing dispatched three Dodge touring automobiles and loaded them with Patton, ten soldiers from the 6th Infantry, and a couple of civilian guides to purchase corn from a farmer in Rubio. After buying the feed, Patton seized the moment, sending the party to the San Miquelito Ranch, where he hoped Cárdenas had returned from his hideout. Patton ordered the soldiers to surround the dwelling and prepare for a fight. As they crouched with their guns at the ready, three Mexicans ran out the door. The Americans opened fire, killing two of them, including Cárdenas. More shots rang out and a third Mexican was felled. There is no way to tell if the bullets from either Patton’s rifle or ivory-handled Colt 1873 single action .45-caliber revolver killed any of the men. But Patton is credited with initiating the operation and he couldn’t wait to tell Pershing, who had no idea what his aide and the other men were up to. Lieutenant Patton and his party rushed back to headquarters with the corpses of the dead Mexicans tied to the hoods of their cars. Patton also carried away Cárdenas’s silver-studded saddle and sword as war trophies, which Pershing allowed him to keep. News of Patton’s feat blazed in the headlines of newspapers in the United States, which proclaimed him the “Bandit Killer.”

From FORTY-SEVEN DAYS: How Pershing’s Warriors Came of Age to Defeat the German Army in World War I by Mitchell Yockelson. Reprinted by arrangement with New American Library, an imprint of Penguin Random House LLC. Copyright © 2016 by Mitchell Yockelson.

Mitchell Yockelson, the recipient of the Army Historical Foundation’s Distinguished Writing Award, is an archivist with the National Archives and former professor of military history at the United States Naval Academy. His work has been featured in the New York Times, Washington Post, and the Los Angeles Times, and he has appeared on 60 Minutes, Fox News, PBS, and the History Channel. He is the author of three earlier books: Borrowed Soldiers: Americans under British Command, 1918, named one of the best military history books by The Independent (UK) in 2008; MacArthur: America’s General, and Grant: Savior of the Union. An historical adviser to the U.S. World War One Centennial Commission, Yockelson regularly leads tours of World War I battlefields for the Smithsonian Journeys and New York Times Journeys series, and frequently lectures on military history. He lives in Annapolis.