If you don't care for roller coasters with inversions, you can blame the French. In 1848 the first inversion in a roller coaster was part of the Centrifugal Railway. Located in Paris, the ride consisted of a sloping 43 foot tall track leading into a nearly circular vertical loop 13 feet.
Most of the early coasters built in the United States were built at Coney Island in Brooklyn, New York. Coney was chosen as a test site for many rides because it was the birthplace of the American amusement park, the modern roller coaster, the dark ride and even the hot dog.
Coney Island’s Flip-Flap Railway, built in 1895, by Edwin Prescott was the first looping coaster in the US. The Flip-Flap reached a neck-snapping 12 Gs at the bottom of its loop, more than enough to induce what pilots call G-LOC, or gravity-induced loss of consciousness. Riders often passed out and injuries were commonplace, soon the Flip-Flap became one of those "No, thanks I'll just watch" rides.
The second looping coaster was Prescott's second effort. Built in 1901, Loop-the-Loop was a vast improvement on the Flip-Flap. The track was made of steel, the loop was larger, and more importantly, it was elliptical. Although the ride was much safer, the ride capacity was a horrid 48 people per hour.
The Loop-the-Loop was unable to live down the reputation of its predecessor and again the public was more inclined to watch than ride. The coaster limped along until World War One, making more money by charging people admission to the viewing area to watch, rather than experience the ride. Eventually the novelty wore off and the looping coaster faded off into bankruptcy.