I watched a woodworking demo at Silver Dollar City near Branson, MO where a guy was showing a special purpose machine driven by a belt from a central shaft in the ceiling. It cut multiple dovetails simultaneously and presumably, there could have been a similar machine for doing box joints.
I've also seen demonstrations (at woodworking shows and at Colonial Williamsburg) of cutting dovetails by hand and I've been amazed at how precise and "machine-like" they were.
My own attempts at doing dovetails by hand have been sloppier than that but they did fit so I guess that's really all that is required.
But I'll get to the point: I second the suggestion to consult the book by Tage Frid. That's how I learned to do hand-cut dovetails. Furthermore, the guy at Silver Dollar City led me to believe that the finger joint (or box joint) was a development of the machine age.
I try to do as much as I can by hand for reasons that I can't really explain. But I'm not terribly good at it. Kind of like my shooting skills. :wink: