Like many breakthrough inventions, air bearings were a by-product of military needs.  You could win a bet by asking a smart guy, "Which U.S. war drove the invention of air bearings?"

The answer is:  The US Civil War.  No way you could lose on that.

The siege cannons and huge mortars designed for the Northern campaigns used more potent powder and larger shells These steel monsters required enormous billets of high strength alloy steel to be cut and milled into these weapons.  It was a new problem, due to size and weight of the steel hunks, causing new tools to be created.  You couldn't spin 5 tons of steel in the lathes of the day.  A clever person (I'm still digging to find a name) developed the use of machined brass pads floating on machined brass runways - the pads being multi-perforated where they rested on the runways, flat brass to flat brass.  These pads were supplied with compressed air (we did have steam and water-driven air compressors) which allowed extreme low friction positioning of the huge billets.  They were then clamped down and milling machines went to work.  Periodically, the billets were repositioned to a more advantageous angle for subsequent machining operations.

The limits of this technology were that the operating surface convexities and concavities couldn't exceed + or - 1 mil (one thousandth of an inch) due to the low lift height (difference between inflated and deflated state), about two mils.  In other words, you need a very, very flat floor for solid air bearings to function.  If you have a zero lift height requirement, and a machined flat surface floor, we can provide solid air bearings.

This is where the technology stayed until the late 50's when the Frigidaire division of GM patented a flexible membrane air bearing allowing some undulations in the operating surface.  Boeing was designing tooling in the early 60's for the what was to be the world's largest airliner, the 747.  The GM air bearings seemed promising and they designed several tool fixtures for building this airplane using that technology.  The GM technology used a "bottom-half-of-the-bagel" inflated membrane whose geometry limited lift height.  While they worked well on some parts of the factory floor, Boeing had to grind down peaks and fill valleys on other parts of the floor.  Boeing assigned a team of engineers to resolve the air bearing problems including inability to pressure adjust for unequal loading at each corner.  They invented a new, full torus (complete bagel shaped unit).  Boeing received a patent for this new and improved air bearing (AeroCaster)which was pressure adjustable, could tolerate twice the former limit of floor waviness and carried about twice the load for a given diameter.  AeroGo was a Boeing spin-off in 1967 to exploit the industrial potential of the new design and remains the world leader in industrial air bearing solutions.  Want to build your own air bearing?