Back when my dad was young he told me he could remember when college was FREE to any state resident, you needed to buy the books, you had to pass and entrance exam, but after that you signed up for classes, and that was it. The teachers were state employees and paid for by the state. And for the record in many places each college has it own entrance exam and if you don't pass you don't get in.
Now I don't know if he misremembered, or if there was some programs at the time but given the amount money most colleges get from the state and federal government there is no real reason college couldn't be free.