Mississippi River

According to Anji, the Mississippi River was "America's major north-south commercial link".

She also noted that it was forced to empty at New Orleans instead of further west by a complicated series of levees. This network was supposed to keep the river from failing but it sometimes failed. (PROSE: The City of the Dead)

Steamboats — typically with large paddles at the rear — were a common method of travel on the Mississippi, at least in the 19th century. (PROSE: The City of the Dead, Coldheart)

Ace had a dream of going up the river in such a boat, and she very nearly got the Seventh Doctor to take her on her dream trip — before another crisis intervened. (PROSE: Timewyrm: Genesys)