The very first slot machine (called 'Liberty Bell') was created by a man called Charles Fay from his workshop in San Francisco in 1887. Slightly smaller than today's average slot machines, Liberty Bell contained 3 reels and 20 symbols and operated pretty much in the same way as today's slot machines. Within a relatively short period of time, Fay's creation became so popular and successful that he began to work overtime in his workshop to meet the demand for his slot machines. Capitalizing on their success, Fay rented the machines to gambling establishments at a 50% commission rate, refusing to sell the manufacturing and distribution rights of his slot machines to gambling manufacturers.

In 1907, Herbert Mills, a Chicago manufacturer created 'Operator Bell', a slot machine similar to 'Liberty Bell' in design. Produced and distributed at a greater rate than Fay's 'Liberty Bell', the 'Operator Bell' slot machines experienced even greater success and by 1910, slot machines were very common in the United States of America. As soon as slot machines had reached a new peak in popularity and became common throughout the USA, new laws were introduced and passed to ban slot machines. In spite of this, slot machines continued to be popular throught America during the 1920s and 1930s. During the late 1940's, Bugsy, a well known gangster, added slot machines to his Flamingo Hilton hotel in Las Vegas where the profit from slot machines eventually exceeded that of table games.

Today, slot machines are amongst the most popular games found in casinos, accounting for over 30% of casino profit.