The Decathlon and Super Decathlon are two-seat fixed conventional gear light airplanes designed for flight training and personal use and capable of sustaining aerobatic stresses between +6g and -5g. The Decathlon entered production in the United States in 1970 as a more powerful and stronger complement to the Citabria line of aircraft.
The Decathlon was designed by the Champion Aircraft Corporation, and is a derivative of the 7-series Citabrias. While the Citabria designs remain successful, Citabrias are not capable of "outside" maneuvers (those requiring significant negative-g loads.) Pilots wanted an aircraft capable of more maneuvers, and Champion introduced the Decathlon in response to this demand.
The Decathlon entered production at Champion in 1972, immediately before the company was acquired by Bellanca Aircraft Corporation, so only a handful were produced by Champion. Bellanca continued production of the Decathlon throughout the 1970s, moving to the Super Decathlon variant during 1976. Bellanca built over 600 of the 8KCAB design before production of the aircraft was interrupted when the company's assets were liquidated in 1981.
American Champion Aircraft Corporation acquired the Decathlon design in 1990, bringing the Super Decathlon version back into production that same year. It is still being produced.
Source: Wikipedia, "American Champion Decathlon", available under the CC-BY-SA License.