As the Rio Grande changed course in the 1800s, it also changed the boundary between the U.S. and Mexico. With the new boundary, the course of history and lives of Americans and Mexicans were altered. For decades, the two countries disputed the boundary change and the ownership of 600 acres, known as the Chamizal. In 1963, a convention formally settled the dispute and the Chamizal was divided between the U.S. and Mexico. Presidents Lyndon B. Johnson and Adolfo Lopez Mateos met to formally discuss the agreement, presumably over a cup of coffee.