General Motors’ familiar contribution to automotive styling, the tail fin, reached its ultimate expression with the 1959 Cadillac.

In 1958, social critic John C. Keats (no relation to the English romantic poet) wrote a comprehensive takedown of the U.S. auto industry called The Insolent Chariots. As he saw it, American cars had ceased to serve their owners. They had grown into grotesque iron monsters and now, in the ultimate triumph of form over function, we were serving them. Just one year later, General Motors introduced the car that, as much as any one make or model could, epitomized all the alleged evils and excesses that Keats detailed in his book: the 1959 Cadillac.

The ’59 Cadillac has been described as not so much a car, really, as a pair of long, towering tail fins that a family could ride in. GM had introduced fins to automobile styling a decade earlier on the 1948 Cadillac, led by GM styling czar Harley Earl and chief Cadillac stylist Frank Hershey. As the story goes, they were inspired by the twin tail assemblies of a World War II fighter aircraft, the Lockheed P-38 Lightning.

So it was only fitting, then, that fender fins would find their ultimate expression around 10 years later on the 1959 Cadillac. Styling for the ’59 Caddy line is generally credited to a team that included Ed Glowacke, Chuck Jordan, and Dave Holls, under the direction of Earl and his successor as GM’s vice president of design, Bill Mitchell.

While the tailfins play the leading role in the ’59 Cadillac’s presentation, the car was grandly overstated and overwrought in every way, from the front to the rear. The bumpers alone were a die maker’s nightmare: heavy and complicated multi-piece steel stampings, chrome-plated and then bolted together. The wheelbase was 130 inches; overall length a ponderous 225 inches, and curb weights exceeded 5000 lbs. To haul all this metal around, for ’59 the Cadilac V8 was upsized from 365 to 390 cubic inches and the output increased to 325 horsepower. On the optional Eldorado V8, boasting a team of three gas-guzzling carburetors, 345 hp was available. A standard Sedan DeVille cost around $5500, more than twice the price of a well-equipped Chevrolet Impala.

On the more common Cadillac models for ’59, the fins were reasonably integrated into the overall visual theme—of a piece, more or less. But on some models, including the hearse/ambulance professional cars and the Fleetwood 75 formal sedan above, the fins appear as vestigal appendages, serving no evident purpose. And at that point the jig is up, if you will. In truth the fins have no actual function on any Cadillac models. You could hack them off the fenders and the car would drive exactly the same, but with improved rearward visibility. This may be urban folklore, but it’s said that one auto executive was seriously injured when he tripped in the garage and fell into his Cadillac’s tail fin.

Meanwhile, there was one Cadillac model for ’59 that didn’t include the giant fins. The top-of-the-line Eldorado Brougham, above, its body constructed in only 99 copies by the Italian coach house Pininfarina, employed a more refined and subdued version of the fin, and it was this general configuration that was adopted by Cadillac across the line in 1960. Just as it peaked, the epoch of the tail fin was passing. Over the next few years, tail fins would disappear from Cadillacs almost completely.