Short answers, pulled from the story.
The oldest known canals were irrigation systems built in Mesopotamia, now part of Iraq. The Indus Valley civilization developed sophisticated storage systems including reservoirs at Girnar around 3000 BC.
This massive project began in 605 AD and finished by 609 AD though some sections existed since 486 BC. The Grand Canal of China remains the longest extant waterway today stretching from Beijing to Hangzhou.
The Bridgewater Canal opened in 1761 as the first major British canal commissioned by the 3rd Duke of Bridgewater. Engineer James Brindley designed this waterway with an aqueduct carrying it over the River Irwell.
Competition from railways starting in the 1830s made smaller commercial canals obsolete for most transport purposes. Railroads began seriously competing in price and convenience by about 1850 ending the American canal building boom.
The expanded Panama Canal began commercial operation on the 26th of June 2016 allowing larger Post-Panamax ships through new locks. A puppet republic called Panama was established in 1903 with a currency named Balboa replicating the US dollar.