The French began construction of the Canal in 1882 but diseases like malaria took the lives of some 20,000 workers and construction stopped just six years later. The United States proposed to finish the job but Columbia rejected the proposal. President Theodore Roosevelt helped spearhead an independence movement along with U.S. Battleship backup. Panama declared its independence in 1903. In return the U.S. was ceded a ten mile wide strip of land in which the canal could be constructed. This area was fenced off with military support. For the next six decades this affluent enclave was separated from Panama. Workers were given housing just outside the U.S. zone and these remain slums to this day.
Protests by Panamanians became frequent in the mid 1970's. Several students died in these demonstrations. In 1977 President Jimmy Carter and General Omar Torrijos signed a treaty that allowed for the transfer of the Panama Canal back to the Panamanian government. This transfer was completed December 31, 1999.
There is a museum that documented the building of the canal. At 3pm the giant tanker ships began moving through the locks. The ships were guided by large train engines that used rails on either side of the canal. Once the ship was in the lock, the water would be flushed out until the water was down to sea level. Then the ship could sail out into the Pacific. Later in the day smaller ships could go through. It is indeed an engineering marvel and tourists lined up to take snapshots. In the harbors there was a constant line of tankers waiting to go through. When a cruise ship goes through the locks, each tourist must pay $200 so the canal generates a sizable income for the Panamanian government.