John August Miller was a famous roller coaster designer. He was born in 1872 in Homewood, Illinois and he passed away on June 24, 1941 in Houston, Texas. He is responsible for over 100 patents developing many of the safety mechanisms still in use on today's roller coasters. During his life, he designed around 60 roller coasters.

At 19 years of age, Miller began working with many influential men in the field of roller coaster design and development including La Marcus Thompson, Frederick Ingersoll , Fred and Josiah Pearce, and Harry C. Baker.

In 1910, Miller designed a device to prevent the roller coaster cars from sliding backward down the lift hill if the chain broke. This device is known as the Safety Dog Chain and is what is used today that makes the infamous clicking sound on wooden roller coasters.

In 1919, he developed the underfriction wheels, which he is most famous for, as these are still in use on every roller coaster today. These wheels are responsible for allowing the coaster to safely reach high speeds, turn quickly, and go upside down without causing harm the ride's passengers. His other inventions included several different types of brakes and bars to lock each one of the cars.

He also built several different roller coasters including: The Dip-Lo-Docus in 1923, Flying Turns in 1929, Cyclone at Puritas Springs, and the Greyhound. The Cyclone at Puritas Springs was located in Cleveland, Ohio. It now has a place on the list of Greatest Lost Roller Coasters at the Smithsonian. When the coaster was active, everything but the platform used to board the coaster was hidden by trees and other foliage, so riders had no idea what they were getting themselves into.

Many of the roller coasters John Miller designed and built are still in use today. The operational roller coasters include: The Racer, The Jack Rabbit, and Thunderbolt, all at Kennywood and designed in the 1920's. Other operational roller coasters include: The Big Dipper, the Coaster Thrill Ride, the Roller Coaster, and the Zippin Pippin. Travel insurance may be a good idea for those who are interested in riding these older roller coasters!

• The Lemelson-MIT program offers an Inventor of the Week segment on John A. Miller.

• Capital University offers the Roller Coaster Almanac detailing many of the roller coasters designed and developed by John Miller.

• Penn State University offers a detailed list of the patents on roller coasters and their devices, including patents from John Miller.

• John Hopkins Magazine, a John Hopkins University publication features an article on John Miller and his contributions to the amusement park world with his roller coasters.

• Chatham University offers a curriculum for High School teachers who want to teach geometry through a field trip to Kennywood, one of the parks where some of John Miller's roller coasters are still actively in use today.

• The State of Tennessee offers a PDF file showing the Registration Form for the National Register of Historic Places for the Zippin Pippin Roller Coaster, located in Memphis.