Panama Canal
Colombia, France, and later the United States controlled the territory surrounding the canal during construction. The US continued to control the canal and surrounding Panama Canal Zone until the 1977 Torrijos–Carter Treaties provided for handover to Panama. After a period of joint American–Panamanian control, in 1999, the canal was taken over by the Panamanian government. It is now managed and operated by the government-owned Panama Canal Authority.
Territories of the United States on stamps
The U.S. Postal Department also used general issue stamps with the territorial name overprinted, such as PUERTO RICO, CUBA, GUAM, PHILIPPINES or CANAL ZONE. Cuba was granted independence, Canal Zone returned to Panama. 
Alternatively, the U.S. issued a 1932 'United States of America' stamp for 18 centavos in the Philippines, 1930 stamps for use in Guam only designated 'Guam Guard Mail, or 1952 'Ryukyus' stamp for 100 yen in Okinawa. The Philippines was granted independence, the Ryukyus were returned to Japan. 
Panama Canal has been featured on several U. S. commemorative stamps, as well as on Panama's own postage. The territory was returned to Panama.