What does "accessible" mean in the 5th paragraph? how do you know?

It means able to be reached or entered because Ford was able to easily make cars more usable by making them easy to drive

In this setting, I believe the word "accessible" means available. I know this because of the context. He was not the first to make the car, which means there were other cars out there, but he was the first to make it accessible, which means that prior to Henry Ford, cars were not readily available to the public. His assembly line made it possible for the average american to have and maintain an automobile.

I hope this helps =)