Why were anti-lock brakes invented?

Answer 1

To make panic-breaking safer - when you stomp on the brake pedal in a car without ABS, you will loose all ability to control where it goes, because your steering wheels will lock up (stop spinning). ABS keeps your tires moving so that you can maintain some control over the direction of your vehicle.

Anti Lock Brake System was first invented for airplanes, given the fact that they have variation of weight on the wheels as speed increases or decreases on the ground while an aborted take off or landing take place. This makes the regulation of maximum positive braking (braking without skidding), very difficult to acheive, mainly if the runway surface is slippery because of water, snow, oil etc.