Watch an excerpt, above, from the new documentary “The Roller Coaster Wars That Birthed a Beast," available now on the Very Local app.It's hard to imagine a world without roller coasters and amusement parks. But for a few decades, roller coasters were on the brink of extinction, brought on by an economic downturn from the Great Depression and World War II.It took the budding amusement park Kings Island in Cincinnati, Ohio, to take a huge risk and build a wooden roller coaster – The Racer – to reignite the renaissance of roller coasters in the 1970s. Roller coasters were all the rage in the 1920s – a period dubbed "The Golden Era of Roller Coasters." Over 1,500 were in operation across the country. Coney Island's iconic "Cyclone" roller coaster was birthed during this time in 1927. But when The Great Depression and WWII hit, expendable income dried up, and fewer people could afford to go to amusement parks. This nosedive in profits for the industry lasted from the 1930s to the 1960s. With no profits to build or repair rides, amusement parks tore down hundreds of roller coasters. However, a beacon of hope was found in 1972, when Kings Island, an amusement park outside of Cincinnati, opened for the first time.Its debut came with the opening of The Racer, a classic out-and-back roller coaster where riders in two cars race along twin tracks."Disney and Six Flags, who were both operating parks, felt that roller coasters were passé, they were carnival, they were done," said Dennis Speigel, the founder of International Theme Parks Services, Inc. The long lines for The Racer caught the eye of a Six Flags representative, which helped them realize how important roller coasters could be, said Speigel.More than 1,000 wooden roller coasters were built around the world because of The Racer's success. But through the 1970s, if Kings Island wanted to stay competitive among bigger parks, the thrills needed to keep getting bigger and better. Soon enough, Kings Island would unleash onto the world two roller coaster monsters that would change history. Download the Very Local app to stream “The Roller Coaster Wars That Birthed a Beast," available now. Visit the Very Local app to learn more, stream local news, and explore more original series. Keep connected to your hometown with the news team you trust and discover original series and specials that explore your community and beyond.Follow Very Local on Facebook, Instagram, and YouTube for more.