United States territorial acquisitions
The Panama Canal Zone was an unorganized US territory located within the Republic of Panama. It was established under the Hay–Bunau-Varilla Treaty in 1903 and disestablished in 1979 under the Torrijos–Carter Treaties. Panama gained full control over the Panama Canal in 1999.
United States invasion of Panama
The United States invasion of Panama, codenamed Operation Just Cause occurred between mid-December 1989 and late January 1990. It occurred during the administration of President George H. W. Bush and ten years after the Torrijos–Carter Treaties were ratified to transfer control of the Panama Canal from the U.S. to Panama by 1 January 2000.