Charles Fey is celebrated for inventing the slot machine in the year 1895. He went on to improve the initial invention when in 1907 he joined the company Mills Novelty which manufactured the Mills Liberty Bell.

The Liberty Bell in its primary shape was made of iron feet of cast iron contained within a container of cast iron. In later improved models, intricate decorated feet came instead of the removed toes.  

The king, queen and jack playing cards were arranged in reel strips on the machine. A bell was inserted into the machine at the beginning and it announced that you had achieved ringing up a prize combination; but this bell was taken out afterwards.

Today, however, a bell has been re-embedded into the current slot machines and is based on the first idea of announcing the jackpot hits to the player by ringing.  

Therefore the original model upon which the current slot machines are based in the United States is the Liberty Bell, is still used today in its original format for the assortment of mechanical games.

The primary simple mechanized arrangement containing twenty symbols fixed on three pre-modern reels have evolved into the arrangements containing hundreds of symbols fixed upon five spinning reels which electronic microchips control and supervise.

The Operator Bell was introduced in 1910 by the Mills Novelty Company who had improvements to the Liberty Bell.

Current slot machines still retain and display a gooseneck-shaped funnel for inserting coins as well as the famous fruit images.

Over thirty thousand machines were manufactured with slots made from cast iron and weighing over one hundred pounds. 

In 1915 the era of cast iron slot machines came to an end when Mills made the decision to produce slot machines made of less expensive wood cabinets.

In the early 1930s the Mills Novelty Company brought in a number of additional changes in the slot machine’s structure and within the slot machine industry it was revolutionary. 

The first change targeted the noise of the machine and how to reduce it. And due to this modification, in the 1930s the machine was nicknamed the silent bell.

The double jackpot was the second modification; this allowed players to win two games successively and fast.

A series of icon themes was invented by Mills which added to the cabinet forms that high-flying colors decorated them.

The machines metamorphosed in this way into attractive and memorable arrangements drawing people to play.

In 1931, the first of such attractions was the Lion Head, and in its wake came the Roman Head and the War Eagle towards the end of the year, while in 1933 the Castle Front was created.