Submachine guns have gone through a distinct evolution over the past one hundred years. Today we will look at these changes, specifically identifying:

- 1st Generation guns from World War One and through the 1930s
- 2nd Generation guns of World War Two
- 2nd Generation guns after World War Two
- 2nd Generation guns adapter to modern polymer manufacturing
- 3rd Generations guns in the form of rifle actions scaled down to pistol calibers