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.
Palmyra Atoll
With imminent opening of the Panama Canal, Palmyra became strategically important. Britain had established a submarine cable station for the All Red Line on nearby Fanning Island. So the U.S. Navy sent to Palmyra, where on February 21, 1912, American sovereignty was formally reaffirmed.