Often called one of the seven modern wonders of the world, the Panama Canal splits the continents of North and South America ...

Panama's voters approved a 2006 referendum authorizing a major expansion of the canal to accommodate larger modern cargo ships. The expansion took until 2016 and cost more than $5.2 billion.

Former President Carter looks over the Panama Canal on June 17, 1978. Carter signed the final Panama Canal Treaties, which gave control of the canal to Panama in 2000.