History of Fifth Wheel Trailers: The Truck-Bed Hitch That Changed Towing
The history of fifth wheel trailers starts long before the RV — with a wagon part, a trucking innovation, and an aeroplane designer who thought a camping trailer should ride like a Pullman car. The fifth wheel is the oldest hitch idea in the industry and, a century on, still the one that carries the biggest, heaviest towables on the road. This is how a coupling borrowed from freight became the defining hardware of the luxury towable, and why the format it created still tops the trailer market today.
If you are shopping the modern version, our fifth wheel buying guide covers today's sizes, pin weights and tow vehicles, and you can browse fifth wheel trailers on RV Frontier as you read.
The name comes from a wagon
The term "fifth wheel" predates the motor vehicle. On a horse-drawn wagon, the front axle assembly pivoted on a horizontal wheel — a flat, circular plate — mounted above it, letting the front axle swing so the wagon could turn in a tighter arc. Four wheels carried the load; the fifth, horizontal one did the steering work, and the expression entered the language so thoroughly that "a fifth wheel" later became slang for something superfluous.
That pivot is the whole idea. A trailer that turns around a point placed over or ahead of the tow vehicle's rear axle tracks more faithfully, resists sway, and puts its tongue load where the vehicle is strongest. Wagons worked it out with horses; trucks and campers would each rediscover it in turn.
Trucks industrialise the idea
When motor trucks replaced wagons, heavy hauliers needed the same trick at larger scale. In 1914–15 the Detroit blacksmith-turned-trailer-builder August Fruehauf built some of the first successful semi-trailers, and by 1916 his company had patented a floating fifth-wheel coupling for commercial trucks. The semi-trailer and its fifth wheel became the backbone of road freight: the tractor carries a substantial share of the trailer's weight on a greased plate in the middle of its chassis, and the trailer pivots on a kingpin dropped into that plate.
That freight hardware matters to RVers because it proved the concept at weights campers would not reach for decades. Everything a modern fifth wheel does — the pin, the plate, the load carried in the truck bed rather than hanging off its rear bumper — is the semi-trailer's arrangement scaled down to a pickup.
Glenn Curtiss and the Aerocar, 1928
The first production travel trailer to use a fifth-wheel coupling was built by an aviation pioneer. Glenn H. Curtiss, co-inventor of the aeroplane era's defining machines and founder of the Curtiss aircraft companies, was a keen hunter and camper. Around 1919 he built a fifth-wheeled camping trailer for his own use, the Curtiss Camp Car, after noticing that aeroplanes towed by their tailwheel — resting over the tow vehicle's rear axle — travelled smoothly.
In 1928 the design became the Curtiss Aerocar, built in Florida and under licence in Detroit through 1940. Instead of a freight plate, Curtiss patented an "Aero Coupler": an inflated aircraft tyre laid horizontally in a frame over the tow car's rear, into whose hub the trailer's pin dropped. The tyre absorbed movement in every direction, giving a large, fully enclosed trailer a ride stable enough for speeds above 70 mph — extraordinary for the period. Fortune magazine called the Aerocar "the Rolls-Royce of trailers" in 1937, and prices matched the compliment: Florida-built Aerocars cost $2,500 and up in 1929, when conventional travel trailers sold for a few hundred dollars.
The Aerocar proved a big trailer could be a fifth wheeler. It did not make fifth wheels common, because almost nobody could afford one.
The idea waits forty years
Through the 1930s–1960s, the travel trailer industry standardised on the bumper-pull: a coupler on a ball at the back of the car. It was cheap, any car could tow it, and trailers were light enough that its compromises — sway, a hinge point behind the rear axle, limited tongue weight — stayed manageable. Fifth-wheel camping trailers appeared occasionally, mostly as curiosities or heavy commercial units, but the format had two problems: it needed a hitch permanently mounted in a truck bed, and it needed a truck worth the name.
What changed was the pickup. Through the 1960s and 1970s American pickups grew heavier frames, bigger engines and genuine payload ratings, and a farming and contracting culture already used gooseneck and fifth-wheel couplings on stock and equipment trailers. RV builders adopted the hardware for campers in the 1970s, and buyers discovered what truckers had always known: a large trailer pinned over the axle tows with a calm that a bumper-pull of the same size cannot match.
Slide-outs and the luxury turn
By the 1980s the fifth wheel had become the industry's premium towable format, and in the 1990s the slide-out room completed the transformation. A fifth wheel's raised front deck — the overhang above the truck bed — creates a split-level floorplan no travel trailer can copy: an upper bedroom or living level, high ceilings below, and vast basement storage in the frame beneath. Slides widened that space further, and builders aimed the format squarely at full-timers and long-stay snowbirds.
Fifth wheels also absorbed the era's biggest trailers. As lengths passed 40 feet and weights passed what a rear bumper could responsibly carry, the in-bed hitch stopped being a preference and became a necessity. The format that had begun as a luxury became the default answer to a physics problem — the same trajectory our broader history of RVs traces across every RV type.
Why the format won: the physics, and the gooseneck cousin
The fifth wheel's long dormancy was never about the idea failing — it was about the tow vehicle catching up. A bumper-pull coupler hangs the trailer's tongue weight behind the rear axle, where it levers weight off the front wheels and gives the trailer a long swing arm to push against. Move the pivot into the bed, over the axle, and both problems shrink at once: the load rides where the truck is designed to carry it, and the trailer follows instead of wagging. Freight had proved this by the 1920s; family cars of the era simply could not use it, because a bed-mounted hitch in a sedan was absurd. Once the pickup truck became a mainstream family vehicle, the RV industry inherited a tow vehicle that already had the mounting point built in.
The fifth wheel also has a close relative worth distinguishing, because the two are often confused. Farm and ranch trailers traditionally use a gooseneck: a long, curved neck reaching down to a ball mounted in the truck bed. The geometry is similar — load over the axle — but the gooseneck ball allows more angular movement on rough ground, while the fifth wheel's flat plate and kingpin give a tighter, more controlled connection on the highway. RVing standardised on the fifth wheel plate, partly for that highway manners advantage and partly because the flat plate suits the quick hitching routine of a campsite rather than a stockyard. Modern fifth-wheel hitches have even borrowed the gooseneck's selling point, with compact single-point designs that leave the bed clear when removed — the format still refining the same century-old pivot.
The fifth wheel today
The modern fifth wheel keeps the Aerocar's essential bargain. The kingpin and bed-mounted plate put 15–25% of the trailer's weight in the truck bed, towing stability is the best in the towable world, and the trade-offs are the ones Curtiss's customers also faced: you give up the truck bed while towing, you need a truck with real payload, and the rig costs more than the bumper-pull equivalent.
Prices follow that premium position: as of October 2026, new fifth wheels typically run from roughly $45,000 for half-ton-towable models to $190,000 and beyond for the largest luxury floorplans. The fifth wheel's century-old coupling is now the hardware behind the most expensive towables in the industry — a long way from a wagon's steering plate, and recognisably the same idea.
Ready to see what the format became? Browse current fifth wheel listings on RV Frontier and compare floorplans, pin weights and prices against the buying guide linked above.