There were fewer people and more land that wasn't being used. It's fairly simple, supply was higher, demand was lower. As our population increased and we developed more and more land, the supply shrunk while the demand grew.
Shall we all wait for covid20 to wipe out enough people that the housing supply overwhelms demand and prices drop?
Land value taxes and Georgism in general are utopian nonsense that have never done any good anywhere at any time. People love to trot them out as solutions to the housing affordability problem but can never show how they would help -- because they can't help!
Building more housing is the only solution, everyone knows it, and weird pie-in-the-sky stuff like land value tax are distractions that ought to be ignored.