In 1848 the United States
and Mexico signed the Treaty of Guadalupe Hidalgo which established
the border between the two nations. Part of that border was the center
of the Rio Bravo (Rio Grande del Norte). Under international law river
boundaries change with normal erosion, but not with alosive
action. From 1852 to 1868 a combination of erosion and alosive action
changed the course of the river and caused a border dispute between
the United States and Mexico that was Finally settled only in 1964.
After nearly a century of dispute President John F.
Kennedy announced that agreement had been reached on July 18, 1963..
This treaty accepted the recommendations of the International Boundary
Commission that, in 1911, granted to Mexico all land south of the Rio
Bravo in 1864. L. B. Johnson signed the Chamizal Treaty on December
The United States of Mexico issued a stamp in 1964
commemorating the restoration of El Chamizal (the disputed area which
takes its name from a desert plant) to Mexico, and to honor President
John F. Kennedy. The background of the stamp shows a map outlining the
Chamizal District and the new border.