This is very low end bicycle by virtue of the stamped dropouts, steel rims, steel cottered crankset, etc. It is almost certainly a contract manufactured, private label brand for a retail chain. However, certain features such a the crankset spider design, front derailleur, sidepull brakes and contrasting head tube place this newer than the boom era models we typically see. I'd place this into the 1980s and possibly even the 1990s. Is it 10 or 12 speed?
There are some obvious issues besides the normal wear and tear. The stem is sitting abnormally high and probably well above the minimum insertion mark. The rear brake caliper is sitting at a strange angle, so either the bridge mounting hole was drilled oversize or at an odd angle. The front valve stem is not sitting square to the rim and will soon be cut, if it not already.