General Motors design chief Harley Earl is generally credited for the automobile tailfin, introducing small fins on the 1948 Cadillac.   Harley credited the look of World War II fighter aircraft for his inspiration, particularly the twin-tailed P-38 Lightning.

The tailfin era of automobile styling encompassed the late 1950s and the 1960s, peaking between 1957 and 1961.   It was a style that spread worldwide, as car designers picked up styling trends from the US automobile industry, where it was regarded as the "golden age" of American auto design.

Tailfins really captured the automotive buying public’s imagination as a result of Chrysler designer Virgil Exner’s Forward Look, which subsequently resulted in manufacturers scrambling to install larger and larger tailfins onto new models.   As jet-powered aircraft, rockets, and space flight entered into public recognition, the automotive tailfin assemblies (including tail lights) were designed to resemble more and more the tailfin and engine sections of contemporary jet fighters and space rockets.

Plymouth claimed that the tailfins were not fins, but "stabilizers" to place the "center of pressure" as far to the rear as possible and thus "reduce by 20% the needs for steering correction in a cross wind".

The most extreme tailfins appeared in the late 1950s, such as on the 1959 Cadillac Eldorado and the 1959 Chevrolet Impala.   Soaring, sharply pointed, and bearing twin round taillights, they engendered a backlash against the look.   Tailfins descended throughout the early 1960s, even adopting a downward slope on the 1965 Cadillacs.   Mostly they disappeared, although in instances a sharp-edged quarter panel meeting a downward sloping trunk created the look if not illusion of fins.  Vestigial tailfins, however, remained on American cars into the 1990s, at least as far as the 1999 Cadillac Deville.