It was well known when I did civil engineering in the mid 90s, I want to say that it was post Northridge that it started to bubble through the code. 50 years i

It was well known when I did civil engineering in the mid 90s, I want to say that it was post Northridge that it started to bubble through the code. 50 years is probably pre-foundation tiedown. Current construction is going to have long sheet metal straps or j bolts into the foundation, I'm not sure what a retrofit will have. An easy thing to check is the hot water tank. If it's not well strapped to studs, then I can't imagine anything else has been done. If it has, then at least you know that has been done, it it doesn't really tell you anything else. I know when I was selling my house in Wa, that was one of the things the inspector looked for, so it's highly probable that it's been done, as its quick and easy. Inspections are the only way to know for sure, but it can be invasive to get into the walls enough to see.