If you stretch this into the two different concept cars, the first one was built in 1962 called the Mustang I. Public didn't like it much so Ford built the Mustang II in 1963 that closely resembled the production model. The first production mustang was built in 1964.
Ford announced (4/24/08) it has built its 9 millionth Mustang. The 2008 GT Convertible Mustang is heading west to be delivered to a dealership in Iowa.
The Ford Mustang, approaching its 45th anniversary on April 17th, 2009, is one of the most widely recognized vehicles in the world. Today, one of every two sports cars sold in America is a Ford Mustang. The Mustang is also Ford Motor Company’s longest-running nameplate. Mustang was introduced on April 17, 1964, at the New York World’s Fair.
Mustang sales hit an astounding 419,000 in its first 12 months on the market, and topped the 1-million mark in the first two years, shattering the sales records of any single model in the history of the automobile.