Hiram P. Maxim invented the silencer in the early 1900's. His iconic product sold in hardware stores for $3.23, with no tax stamp. While Maxim himself called the product a silencer, it did not silence the firearm, only suppressed the sound to safer levels.
During the Great Depression, it was feared silencers would be used for poaching, and the NFA (National Firearms Act) was passed, giving silencers the well-known $200 tax stamp (at the time, equivalent to $3,000 by today's standards).
The $200 tax stamp remains today.
The eight states that currently do not allow individuals to own silencers are California, Delaware, District of Columbia, Hawaii, Illinois, Massachusetts, New York, New Jersey, Rhode Island, and the District of Columbia.
*If you are an FFL dealer, manufacturer, peace officer, or member of a law enforcement agency or other government agency, there are additional states where you can own a silencer.