The first slot machine called "Liberty Bell" was invented by Charles Fay. He created this at his workshop in San Francisco in 1887. This slot machine was bit smaller than the present one. This slot machine, Liberty Bell had 3 reels and 20 symbols and love it is operation was the same as today's slot machines. In relatively short time frame, Fay's creation became popular and successful.

A slot machine "Operator Bell" similar to "Liberty Bell" in design was created in 1907, by Herbert Mills. He was a Chicago manufacturer. This slot machine had experienced a better success. In 1910 slot machines became common throughout United States of America.

A slot machine is a mechanical device which has varying number of circular reels of different dimensions. These reels have various symbols on it either painted on or they're attached to it. There may be any symbol although the most usual designs are cherries, bars or even the jackpot symbol number 7.