Like many technologies found in cars, Anti-lock Braking Systems were originally developed for aircraft. It’s not a good idea for a plane to lock its wheels on landing!
The first systems were developed in the 20s by Gabriel Voisin a French car and aircraft engineer specifically for planes. One of the earliest systems was developed by Dunlop the tyre company. Called Maxaret, it was found on a number of cars including the Jensen FF of the mid 60s but wasn’t really reliable.
They concept of ABS is the automating of a braking theory called Cadence Braking. This is something that was taught to race car drivers to get the maximum from their brakes. Basically, the driver pumps the brakes to reduce the distance to stoppage. The maximum braking pressure is applied to the brake disc a fraction of a second before the disc locks up. So ABS automates that concept so that the driver doesn’t need to, and it smoothes out the process.
Chrysler and Mercedes both developed systems in the 60s and 70s that were more reliable and it is the Mercedes design that has become a standard for most vehicles.
Today’s systems use a lot of electronic sensors to determine
speed, grip and direction and they are usually fitted in conjunction with
traction control or electronic stability systems. However, as I discovered with
a rental car, if the suspension is sloppy it completely negates the power of
ABS. If the cars weight moves and wheels become light, then they will lock up
because there is no balance in the chassis.