Since 1918 the wall has continued to evolve in Ambos Nogales. Before the battle, other than temporary fences, only a solitary border monument had marked where the two nations met. But afterwards, a simple chain link fence went up along International Avenue to direct people to “Legal Points of Entry.” As the years passed, the fence slowly sprouted lampposts, all the better to illuminate illicit passages. When prohibition created demand for alcohol in the U.S. and guns and money in Mexico, the fence started to snake further out towards the hills around town. Two seedling trees grew to maturity between the old guard posts, and larger checkpoints went up a block west to handle the new influx of automobile traffic between the countries. Chinese immigrants, banned from citizenship in the U.S. since 1892 cut holes through the fence, and started venturing even further out into the deserts and canyons to evade detection, finding work in the agricultural fields and construction sites of the Southwest. But even in 1943, when they became eligible for U.S. citizenship, workers from elsewhere still crossed. So a new, even taller fence was built, and soon barbed wire topped that fence, and the two trees growing between the guard towers were cut down for better visual control. As Nogales became the largest site of cross border commerce in Arizona, the Mariposa Port of Entry was built further west, and a concerted effort to divert extra legal border crossings led the government to install a new steel bollard fence. The World Trade Center attacks on September 11th, 2001, brought a massive influx of new recruits into the revamped Customs and Border Patrol, while semi trucks idled for hours under new inspection protocols. Fewer people came to the old Morley Avenue crossing. Updated guard posts were built, but the buildings on either side have remained the same. Older now, and with more wear. Barely visible over the security cameras and razor wire. Tunnels were built into the Nogales sewer systems and ultralights flew north over border ranches carrying drugs for Mexican Cartels. People came by foot, bicycle, and truck to cross the rugged hills west of town, and the wall continued to stretch out, slithering through the canyons of the Atascosa Highlands.

            The men who set the first chain link along International Avenue would have strained to imagine that their fence would one day run for miles over grassy slopes and down catclaw choked ravines, up loose granite slopes, and across the tops of sheer canyon walls. Far from Nogales, a series of cattle fences, vehicle barriers, and steel bollards cut across this dramatic landscape. On a hot, August day over 100 years ago, a man named Zeferino Gil Lamadrid passed by shops brimming with patrons from two nations. But in November 2020 many of the businesses along Morley Avenue are closed and shuttered, and the border is as quiet as it was on that August day in 1918, after the shooting stopped, and the dust settled.

            As Zeferino Gil Lamadrid walked South down Grand Avenue with a large parcel under his arm, dust kicked up with each step against the dry dirt street. Tensions had been running high between the residents of Ambos Nogales, a binational town straddling the US-Mexico boundary and though Zeferino was a carpenter known to work on both sides of the border, he couldn’t be sure if he’d be met with a kindly wave or a suspicious glare these days.

            Like so many Nogalenses Zeferino lived daily life on both sides of the boundary line. But things had become harder in recent months. The U.S. entered the war raging in Europe, and the disclosure of the Zimmerman telegram sparked paranoid suspicions of German spies infiltrating America from Sonora. The soldiers and inspectors stationed along the border had become more and more aggressive to Nogalenses who regularly crossed the line to work, shop, and visit family in southern Arizona. The revolution in Mexico had already seen two battles rage in Nogales, with bullets occasionally flying into the walls or windows of businesses on the U.S. side. The first fence that went up along International Avenue in Nogales was put there by the Mexican government to slow the flow of U.S. manufactured guns and ammunition to rebellious armies and Indigenous resistance groups. Instability along the border and the increasing presence of soldiers, who were outsiders to this otherwise tight knit community, contributed to rising animosity.

            Newly arrived soldiers complained that the Nogalenses would heckle them on the street. Locals claimed that the soldiers harassed them at the border and engaged in drinking, gambling, and prostitution. In 1915, an American soldier stumbling out of a bar bumped into a local, and words were exchanged, though what they were no one was sure. Whatever was said must have been heated, because the infuriated soldier leveled the local and all hell broke loose across the international boundary as a result. The newspaper reported that,

            “Several hundred American soldiers engage in a riot on the streets of Nogales tonight as the result of a rumor that the Mexicans had threatened to take their guns away. Ten Mexicans were assaulted before the officers got control of the men. One American is reported slain in Nogales Mexico, by infuriated Mexicans… “Run all the Mexicans across the line” was the battle cry.” 200 Mexicans either fled or were chased across the boundary before the officers got control of the mob.” (LA Times august 15th 1915)

            Over the following years, the American army launched two incursions into Mexico, which prompted increased distrust of U.S. government intentions towards Nogales, Sonora and precipitated the building of defensive entrenchments on the hills flanking International Ave. New wartime trade restrictions limited what Sonorans could buy and take home from Nogales, Arizona and the effects were felt hardest not by the feared German spies but by the average Nogalenses who lost access to everyday goods, and by business owners who relied on the cross boundary traffic. New passport requirements disproportionately affected Nogalenses who previously traveled north and south of the international line across the town’s open streets freely. Increased security by non-local, typically non-Spanish speaking soldiers also led to deaths on the border, as jumpy troopers hoping to catch German saboteurs ended up firing on average citizens. Armed border guards replaced formerly cordial relations and muttering from both sides of the line warned of imminent violence.   

            Early in the evening of Tuesday, August 27th 1918, Zeferino walked south through the sweltering late summer heat past the guardhouse, where Customs Inspector Arthur Barber and Infantryman William Clint were standing by. Word was that a revolutionary newspaper inciting violence against the Mexican government was being printed in Nogales, Arizona and smuggled south, and just a few days before a man had been stopped carrying $100,000 in cash. Both men had read about the Zimmerman telegram, a secret communication from German high command to the Mexican government promising recognition of Mexico’s claims to the Southwestern United States, which had been lost in the 1850’s, if Mexico would declare war on the U.S. Daily reports were coming in of the American Expeditionary Force fighting in the trenches of France, and yet here these men were stationed at a dusty backwater, an ocean away from glory. They were restless for action.

            Looking up from his conversation with Private Clint, Arthur saw a man walking around the short, barbed wire fence that had been put up on International Ave just days before to prevent further shootings. The man had a package and, from this distance, Arthur thought he saw something tucked under his shirt. By the time Arthur reacted, the man was already stepping into Mexico. Arthur motioned toward the crosser, yelling, “STOP!” Zeferino stopped. But two Mexican customs inspectors approached and ordered him to keep going. Zeferino took another step. Arthur unholstered his pistol, and followed by Private Clint, walked just past the border line. Stuck between the two armed groups Zeferino’s heart was in his throat, sweat soaked his brow. The men were yelling at each other and at Zeferino, “Come back here immediately for inspection!” “He’s a Mexican in Mexico!” “Come back!” “Keep walking!”

            The U.S. army private leveled his Springfield rifle at Zeferino. Close enough that he could see dust on the wood stock of the weapon. A shot went off. Zeferino didn’t know who fired. He didn’t even know if he was hit. He dropped to the ground and was nearly blinded by the dust kicked up as boots scurried around him. The Mexican guard commander Gallegos fired on Private Clint, dropping him to the ground. Inspector Barber returned fire into the group of Mexicans, killing Gallegos and a young guard named Andres Cecena. Cecena crumpled to the dirt, his boyish face turning towards Zeferino as his skin grew pale. Zeferino, blind with panic, jumped up in the midst of the firing and bolted south leaving the deafening sounds of rifle blasts and the cries of the wounded behind him.

            For two hours International Avenue turned into a homegrown WW1 Battlefield. Soldiers and armed civilians poured in from both sides, and the chaos sent bullets flying into nearby homes and shop fronts. 16 year old Maria Esquival was hanging laundry in her family's yard when she heard what she thought were fireworks in the distance. She wondered what they were celebrating, and looked to see armed men sprinting towards International Ave. Maria heard a crack, and fell motionless beneath the clothesline moving softly in the evening breeze. It's not recorded which direction the shot that killed her came from, but with the madness taking place all around her it would have been hard to know.

             Nogales, Sonora mayor Felix Penaloza was eating at a restaurant near the border when he heard the firing. He was an experienced frontier town civil servant, and he knew immediately that an incident on the border had gotten out of hand. Mayor Penaloza grabbed a white cloth and wrapped it around his cane as he made his way northeast along a narrow street. He shouted for the armed Nogalenses to put their guns down, to stop the fighting. He begged and pleaded with citizens as they ran blindly towards the gunshots, well past reasoning with. Most of the town's professional troops were away fighting rebels near Sasabe, and the situation was far beyond his control. Still he made his way toward International Avenue, a makeshift white flag waving above his head as bullets carved pockmarks in the walls around him. Somewhere across the line, an American rifleman saw the old man, adjusted his aim, and squeezed down the trigger. Felix Penaloza had led parades, and met U.S. officials on the exact spot where he now lay bleeding. Citizens came running from cover and Mayor Penaloza was carried into a pharmacy where he soon died from his wounds.

            Machine guns went up on balconies. The famed buffalo soldiers of the 10th cavalry charged up the hill east of town to drive out snipers firing down onto American positions. Civilians on both sides got involved. Patsy Sutton witnessed the battle from the upper story of a nearby hotel, and recalled seeing, “a little old lady on her porch on the Mexican side, with a large piece of handiwork in her lap. As the American soldiers passed, she reached under the cloth, drew out a pistol, snapped off a few shots at the soldiers, replaced the firearm, and continued watching and working.” Officials on both sides sought channels through which to negotiate a ceasefire, but after the American commander on the scene threatened to march into Sonora and burn Nogales to the ground, a white flag went up over the customs house of Nogales, Sonora. The border was closed for the remainder of the day, and throughout the evening snipers occasionally sent bullets across the line.

            At least 7 Americans died, with 28 wounded. Historical accounts on the number of Mexican casualties vary greatly from 12 to 129 killed, with as many as 300 wounded. The battle prompted both governments to champion the building of a fence that would go up along International avenue, creating the first permanent barrier and the mother of all walls along the US-Mexico border.

Historical postcards of International Avenue in Ambos Nogales