Just a few recollections...forgive me if I'm off a year or two.
Sprinklers: Sprinklers were quite often not required in commercial and residential applications...until the '68 fire at Chicago's McCormic Place Convention Center focused attention on them.
As late as '78, the NFPA was in conflict with a reformer named Patten, who argued that the sprinkler code was only interested in property protection, and not in saving lives. This was about the time the battery-powered smoke detector was making its' own mark. Eventually, Patten won the argument, and a sprinkler code was written, and products developed, for household applications.
Even today, the use of sprinklers in residences is spotty....often with only the public areas so protected.
Firestopping: As a result of the '71 fire in the Harpers Ferry nuclear power plant, firestopping began to get some serious attention. Until then, I'm not even sure intumescent caulk even existed....the fire started when a plumbers' candle, used to check for air leaks, ignited the spray foam that was used to seal penetrations.
I hope my recollections are better than my answer to this "test"....I sure blew this one!
