The automobile marketplace was changing significantly during the early 1960s and became highly competitive in the smaller-sized car segments. The domestic Big Three automakers (General Motors, Ford, and Chrysler) were responding to the success of American Motors' compact Rambler American and Classic models that made AMC the leading maker of small cars for several years and increasing Rambler on the 1961 domestic sales charts to third-place behind Chevrolet and Ford. The innovative Chevrolet Corvair and the Chevy II, which was designed to compete with Ford's Falcon, were losing ground. Ford released the mid-sized Fairlane in 1962, to which Chevrolet responded with the 1964 Chevelle based on a new A platform design. Riding on a 115-inch (2,900 mm) wheelbase, the new Chevelle was similar in size, simplicity, and concept to the standard-sized 1955–1957 Chevrolet models. The Chevelle was the U.S. auto industry's only all-new car for 1964 and was positioned to fill the gap between the small Chevy II and the full-sized Chevrolet models. Introduced in August 1963 by "Bunkie" Knudsen, the Chevelle filled the gap for Chevrolet with sales of 338,286 for the year.