Panama Canal opened

In 1906, American engineers decided to construct a lock canal and used the next three years developing construction facilities and dealing with tropical diseases in the area.

Construction of the 40-mile-long canal began in 1909, one of the largest construction projects of all time. The Panama Canal was opened on August 15, 1914. But Panama pushed to revoke the initial treaty. Finally, in 1977, a treaty was signed to turn the canal back over to Panama on December 31, 1999.