Just looked at a 1957 house. As you might guess, there was 2-wire romex and (nice surprise) and FPE panel. Here's what has me curious:
Every room seems to follow the '12 ft rule' regarding receptacle spacing on three of the four walls. The remaining wall typically has about 6ft. of wall exposed between the open door to the room, and the door to the closet. No receptacles are in this space, or in the remaining 30" behind the door swing.
I can only guess that, in 1957, this wall was not required to have a receptacle. If this guess is correct, can anyone identify the first NEC edition that did require one?