Chrysler Corporation introduced Plymouth in 1928 in the same price bracket as Chevrolet and Ford. In Plymouth's early decades, they sold on par with the main competition.
The Plymouth brand had been known for good quality, but with the new styling in 1957 came also very bad quality, a problem that it took the brand a long time to rectify.
In the latter years the Plymouth brand was diluted, as has been and is the practice of many car manufacturers, by rebadging; i.e. slightly changing the front and rear fascia's. Most of the Plymouth models being sold in the brands last dozen years were basically rebadged Chrysler, Dogde and Mitsubishi models; e.g. Chrysler Town & Country became Plymouth Voyager, Dodge Neon became Plymouth Neon and Mitsubishi Galant/Lancer/Mirage, depending on generation, became Plymouth Colt.
DaimlerChysler AG ended the Plymouth brand in 2001.