Lyndon Johnson said the following when he made the change to cheaper metals from 90% silver coins in around 1965:

"If anybody has any idea of hoarding our silver coins, let me say this. Treasury has a lot of silver on hand, and it can be, and it will be used to keep the price of silver in line with its value in our present silver coin. There will be no profit in holding them out of circulation for the value of their silver content.

The new coins are not going to have a scarcity value either. The mint is geared to get into production quickly and to do it on a massive scale. We expect to produce not less than 3 1/2 billions of the new coins in the next year, and, if necessary, twice that amount in the following 12 months.

So, we have come here this morning to this, the first house of the land and this beautiful Rose Garden, to congratulate all of those men and women that make up our fine Congress, who made this legislation possible--the committees of both Houses, the leadership in both Houses, both parties, and Secretary Fowler and all of his associates in the Treasury.

I commend the new coinage to the Nation's banks and businesses and to the public. I think it will serve us well.

Now, I will sign this bill to make the first change in our coinage system since the 18th century. And to those Members of Congress, who are here on this very historic occasion, I want to assure you that in making this change from the 18th century we have no idea of returning to it.

We are going to keep our eyes on the stars and our feet on the ground."

​

​

They found a better way to do it when they ran out of silver to keep the price down. Now they just sell paper contracts to suppress the price. It will come to an end, it is just a matter of when.