Just a boring bit of Trivia -
The very first slot machine invented was in 1895, in San Francisco, by a Bavarian immigrant named Charles Fey. It was like the one pictured above but had a single wheel. Four years later in 1899, Fey came out with the first three reel device that operated by inserting a coin and pulling an arm. Fey named it the Liberty Bell and it was the forerunner of the reeled slot machines we see today.
Back then the law did not allow one to patent a gambling device so Fey refused to sell his machines out of fear that someone might reverse engineer it and go into competition with him. Instead, he put them in bars around San Francisco but kept the only key. Fey would then go from bar to bar, open the machines and split the proceeds with the house.
All was fine until the Great 1906 Earthquake which destroyed much of San Francisco. Fey went from bar to bar, removing his machines or what was left of them from the wreckage. He retrieved all but one, which was mysteriously missing from a place on Market Street. On the one year anniversary of the earthquake, the Mills Machine Company of Oakland, California (across the bay from San Francisco) announced they would be selling the Mills Liberty Bell Slot Machine. It was a reverse engineered, exact duplicate of Fey's Machine. Now Fey knew what happened to his missing device. Other manufacturers purchased the Mills machine, copied it and from there, companies like Jennings, Pace, etc., spring up. 127 years later you see what slot machines have evolved to today.