Why was The Green Monster at Fenway Park was originally built?

The Green Monster at Fenway Park was originally built to prevent viewing games from outside the park due to the increase in popularity of baseball at the time. The owners of Fenway Park decided to construct a high wall in left field, which eventually became known as the Green Monster. This was done to control the number of spectators and ensure that people would have to buy tickets to watch the games, as many fans were finding vantage points outside the park to watch for free. The Green Monster continues to be an iconic feature of Fenway Park and one of the most distinctive elements in all of baseball.