In 1903, the U.S.-backed revolutionaries in western Colombia revolted and created the independent country of Panama, which was immediately recognized by the United States. The newly independent Panama gave the United States use of a 10-mile (16- kilometer)-wide strip of land across the Isthmus of Panama, where the United States built the Panama Canal. The United States maintained control of the Panama Canal and its surrounding land, called the Canal Zone, until 1999, when a 1977 agreement between the United States and Panama officially took effect and turned the canal over to the Central American nation.