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.

Historical postcards of International Avenue in Ambos Nogales