People started using gasoline once the gasoline engine was invented.
Gasoline started being used in the year 1892 which is when the automobile was invented.
However automobiles were not widely used then and gasoline was not as widely used either.
It wasn't until around 1920 when vehicles were more widely used and gasoline consumption really went up.
Gasoline is a byproduct of crude oil.
Crude oil is extracted from the ground deep down from drilled wells which is then pumped up to the surface and then put in tanks and barrels.
Then the crude oil travels to a refinery where the gasoline is then made.
Propane as well as your motor oil, heating oil, Diesel fuel etc is a by product of that oil.
Before gasoline was used in vehicles and combustion engines the gasoline was thought of as a waste product and discarded.
But now gasoline is a billion dollar business.