2. Panama Canal Zone
For much of the 20th century, the Panama Canal Zone stood as a vital American possession. From 1903 to 1979, the U.S. governed this strategic strip, controlling passage between the Atlantic and Pacific Oceans—key for both trade and military movement. The landmark Torrijos-Carter Treaties paved the way for the Zone’s return. By 1999, Panama had full sovereignty, ending nearly 100 years of American administration but not the canal’s global significance.
