The late 1800s saw the beginning of commercialized public transportation, and electric traction (trolley) companies began to appear in American cities. Electric light and power companies charged the traction companies a flat monthly fee for electricity, regardless of how much or how little power the trolleys used.
Naturally, the trolley magnates became frustrated because without commuters, little demand existed to operate trolleys during the weekends. But by building an amusement park at the end of the trolley line, the public was enticed to ride the trolleys on Saturdays and Sundays, thus creating more revenue for the traction companies.
Soon hundreds of trolley parks were in operation throughout the United States. However, only twelve remain.