The first guns were crude small cannon. Best indications are that they originated in China, about 1100 AD- roughly 1000 years ago.
Like any other product, guns are manufactured to be sold. Buyers can be private citizens, business entities, or governments.
a factory
During which era? Germany manufactured several types of guns throughout the years, whether it's the Dreyse Needle Gun, Luger pistol, Mauser rifle, MP38 and MP40 submachineguns, MG34 and MG42 machine guns, Heckler & Koch firearms, etc.
Raw materials, workers, bueprints.
Every corner of the globe
There is no one single location.
Tobacco and Cotton were manufactured in South Carolina during the 13 colonies era.
HD Folsom or Crescent.
The Iver Johnson Company
Gunsmiths don't make guns - they may assemble them from previously manufactured components, but they don't actually "make" guns. Factories make guns.
Manufactured goodsGuns
Don't listen to him! Mercury Co.