Why was relationship between railroads and amusement parks?

Railroads were looking for a way to increase their weekend business; people used the railroad to access weekend attractions..... it was a match made in heaven for both.

The old woman smiled. "Emile kept his promise. A few years later, he made a deal with the railroad company, which was looking for a way to increase its riders on the weekend. That's how most amusement parks were built, you know."

Eddie nodded. He knew. Most people didn't. They thought amusement parks were constructed by elves, built with candy canes. In fact, they were simply business opportunities for railroad companies, who erected them at the final stops of routes, so commuters would have a reason to ride on weekends, You know where I work? Eddie used to say. The end of the line. That's where I work.