Short answers, pulled from the story.
Bakken opened its gates to the public in 1583. This event marked the birthplace of the modern amusement park and established a permanent destination where mechanical rides coexisted with landscaped gardens and live music.
The World's Columbian Exposition of 1893 in Chicago introduced the concept of the enclosed amusement zone known as the Midway Plaisance. This fair unveiled the first steel Ferris wheel and established a template containing rides shooting galleries and games of chance that would be replicated for decades.
Sea Lion Park became the first permanent enclosed entertainment area regulated by a single company in 1895. It charged admission to enter the park in addition to selling tickets for rides within it and set a model quickly adopted by competitors like Steeplechase Park and Luna Park.
Disneyland opened on the 17th of July 1955 and welcomed its one millionth guest just two months later. This financial success reinvigorated the amusement industry by shifting the focus from simple rides to immersive storytelling and themed environments.
The Wizarding World of Harry Potter opened to the public in 2010 after being announced in 2007. This project made Universal Orlando a major player in the theme park landscape by demonstrating that fans were willing to pay for immersive experiences that honored the source material.
Amusement parks abandoned the ticket system with labeled tickets A through E in 1982. This change replaced the pay-as-you-go scheme with a single admission fee that grants access to most attractions as often as visitors wish during their visit.