They stopped making silver coins in 1964, but people still spending them. Were still kind of common through the 70's. Watch your change, you occasionally still pick one up. Plenty of people buy rolls of coins from banks, just to sort through, and get lucky often enough to keep it interesting (can think of many other things to do myself).
Just because it's a newer house, doesn't really tell what was sitting there before, or what the land was used for. Old houses can't always be fixed up, some people just want modern. Got to figure old houses have been a focus of treasure hunters, since the hobby began, might have been hit pretty hard over the decades.
Hunt where you can, and just have fun.
