This is a handmade youth cardigan cowboy sweater.  I'm not sure what size it would be considered since there are no tags since it's handmade.  It measures about 39 inches from arm to arm and about 17 inches from shoulder to waste.  I'm guessing this is from the 60s or 70s.  It is based on a knitting pattern from Mary Maximprinted in the 1960s.

See pictures for more details.  Happy to answer any other questions I can about it.