The shifting river forced Mexican and US officials to confront difficult questions. When the Rio Grande changed course, did the boundary move with it? Who controlled the land on either side? As they had in the 1840s, the two countries again made conflicting claims to disputed territory. Over the next century, tensions ebbed and flowed as leaders struggled to resolve the conflict.
In the 1850s, gradual erosion and severe flooding shifted the course of the Rio Grande. This created uncertainty about who owned territory along its banks. Eventually, the river flowed south of a piece of Mexican land known as El Chamizal. It became the heart of a boundary dispute for the next hundred years.
Chamizal Dispute Begins
In 1864, flooding pushed the Rio Grande further south into Paso del Norte (renamed Ciudad Juárez in 1888), beginning a century of formal dispute. Across the river, US residents of El Paso, Texas moved into the land known as El Chamizal. Jurisdiction of this land remained in question. Mexico’s President Benito Juárez lived in exile in Paso del Norte between 1865 and 1866 because of the French occupation of Mexico City. During this time he became aware of the effects of the flood. In 1866 his representative addressed the US Secretary of State about sovereignty of El Chamizal.
In the Convention of 1884, Mexico and the United States reaffirmed the river’s deepest channel as the international boundary. For the first time, the new treaty also acknowledged the river’s changing course. If the river channel moved gradually over time, the boundary moved with it. If the river shifted suddenly, the boundary remained along the previous course.
The United States and Mexico established the International Boundary Commission (IBC). It addressed issues caused by changes in river channels used to mark the boundary. The IBC became the International Boundary and Water Commission (IBWC) in 1944.
Case No. 4
The IBC heard the claim of Mexican landowner Pedro Ignacio García. It became known as Case No. 4. The IBC could not reach agreement about which country had jurisdiction over his land in El Chamizal. The conflict continued. Case No. 4 became the focus of the 1911 arbitration.
By the 1890s, the Rio Grande made a dramatic bend east of downtown El Paso, Texas. In 1899, engineers from both countries dug a channel across the bottom of the meander to reduce the impact of flooding. The international boundary remained along the former riverbed. This left an “island” of Mexican land jutting north into US territory. During American Prohibition in the 1920s-30s, the area attracted drinkers and cross-border smugglers. Mexico erected a fence along the perimeter in 1940. Look for the remaining concrete fence posts along the memorial’s northwest corner.
Caught In Between
The Banco Convention settled ownership of bancos, lands left between old river channels and new ones created by flooding. This treaty enabled the two countries to exchange some land. It did not address the dispute over El Chamizal.
The United States and Mexico argued the Chamizal case before the IBC. Commissioner Eugene Lafleur from Canada joined Anson Mills from the United States and Fernando Beltrán y Puga from Mexico. By majority vote, the Mexican and Canadian commissioners awarded Mexico the land that was south of the river before the 1864 flood. The United States objected on legal grounds despite previously agreeing to accept the final decision. The conflict persisted for another fifty years. From 1911 to 1963 every US President tried to reach a settlement.
In the Rectification Convention, Mexico and the United States agreed to straighten and shorten a section of the Rio Grande in the El Paso-Juárez Valley by 67 miles. The Chamizal question remained a separate and unresolved issue. Again, numerous parcels of land were exchanged, and the precedent for a solution was set.
Alliance For Progress
Against the backdrop of the Cold War, US President John F. Kennedy met Mexican President Adolfo López Mateos in Mexico City in June 1962. Seeking a closer alliance, they committed to ending the persistent Chamizal dispute.
Learn More About The Cold War
Last updated: July 20, 2020