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.
Hay–Bunau-Varilla Treaty
This treaty was a source of conflict between Panama and the United States since its creation. The Canal Zone became a racially and socially segregated area, set aside from the country of Panama. The push for environmental determinism seemed to be the best framework to justify American practices in Panama. The conflict from the treaty reached its peak on January 9, 1964, with riots over sovereignty of the Panama Canal Zone. The riot started after a Panamanian flag was torn during conflict between Panamanian students and Canal Zone Police officers, over the right of the Panamanian flag to be flown alongside the U.S. flag. U.S. Army units became involved in suppressing the violence after the Canal Zone Police were overwhelmed. After three days of fighting, about 22 Panamanians and four U.S. soldiers were killed. This day is known in Panama as Martyrs' Day.