West Mifflin PA: View of the Kiddieland Express train at Kennywood Park. The Stewart family visited Kennywood during the summer of 1956. Kennywood Park is one of the oldest amusement parks in America, founded in 1898. Kennywood Park was a big part of our childhood in the Pittsburgh area. At the end of each school year, most school districts had a Kennywood Park Day. The rides included the roller coasters; Jackrabbit, Racer, and Thunderbolt along with the infamous Old Mill where you could steal a kiss or two. Kennywood was designated a National Historic Landmark since 1987