Today thought of as tools for elite military units or vast international criminal organizations, Silencers (more accurately described as surppressors), were developed in the early 1900s.
Hiram Percy Maxim received the patent for the first firearm suppressor in 1909. Surprisingly the silencer is actually closely related to the development of the car muffler, which was originally called the car silencer. The two devices share a lot in common from an engineering perspectively. Both devices mitigate noise by diverting expelled gases. Here is the first patent for the Maxim Silenced Firearm
What is strange about this technology was its original intended use for application on firearms that would be used in urban and rural areas of the US. Two unique conditions existed in America in 1900s that made the early concept of the silencer attractive for many of Americans. A lot of Americans owned guns due to the industrialization of gun manufacturing and there was few regulations as to attaining them and many Americans were moving out of rural areas into more urban areas. This caused a problem because, while the carry of a firearm was widely accepted, the sound of the gunshot was a great disturbance and often a crime. So it seems clear in Maxim’s design that he intended this new invention to be used by a more metropolitan gun owner who perhaps was fond of hunting and sporting with them. Here is a brochure that you can see is clearly targeted for civilians.
It would not be until World War II when the US began to look seriously at the use of silencers by the military for clandestine operations. The father of modern US intelligence, William Wild Bill” Donovan would introduce this invention and its potential to Franklin Roosevelt. Below is a small .22 pistol developed for the Clandestine missions of the OSS
This signaled a shift in the characterization of Silencers in America from civilian use to military use.