Slot machines used dollar coins most of the time. In 1964 the "Silver Dollar" was worth more in silver content than a dollar. At one point some casinos were seeing 50,000 dollars walking out of the casinos each day! in 1964 casinos in Nevada were given the right to mint tokens. in 1965 many of the big casinos had tokens minted.

This changed in the early 70's when the Ike Dollars were minted. In 1978, when the dollar coin was going to change to the Susan B. Anthony dollars, casinos were allowed to go back to having tokens minted.

TITO became big in the in the 2002/2003 time frame (but some casino used them much earlier).

There are some casinos today who still have a few banks of dollar machines that have tokens. Greek Isle Casino was the last casino (that I know of) that still used Ike dollars in their Wheel of Fortune Slot Machine......used to love going in there, drop a Twenty and take the Ike Dollars home.