I thought it might be interesting to build up a picture of just how widespread the permit & inspection system has been in the past compared to today.

So, if your jurisdiction has inspections for new wiring and/or for modifications and extensions to existing systems, when were those requirements introduced?

If there has been a clear distinction between, say, permits required for electricians doing work vs. no inspections for a homeowner working on his own property, let's hear about that too.