I have a 2016 hyundia accent sedan, when I took my car in to get a oil change the mechanic said you only had about a quart to a quart and a half of oil in your car. Could driving with that amount of oil in my car damaged my engine at all? This car means the world to me and I'm freaking out a little , google says my car takes 3.8 quarts, I live in southern California so there isn't a whole lot of uphill and downhill roads.....
There is a theory that says the minimum amount of oil needed is enough to fill all the oilways and with just enough to cover the oil pump inlet, but that assumes that the engine stays level - like on a test bed.
But real engines don’t do that because of hills etc and also the oil system is designed as the internal cooling system for the pistons etc
So, the amount of oil in the sump is set to allow for gradients, cooling and bringing any particles of dirt back - and that is why there is also a filter.
In your case you might have been lucky and no serious damage was done except for, most likely, reducing the life a bit. Lesson learnt: keep checking the level, once a week is good and before a long trip.