50 years ago was 1964. On March 10, 1964, the very first Ford Mustang rolled off the production line. So logically, it's the 50th anniversary of the Ford Mustang!
Ford Mustang with its features and styles has lured a lot of people which is understandable by the number of years it has completed. The Mustang Trailer at http://www.themustangtrailer.com/ also celebrated this 50th successful year of Ford Mustang by supplying variety of apparels with a 50th anniversary logo on it which was appreciated by most of the Ford Mustang fans.