Factual error: In the remastered DVD editions, on Doc Baker's wagon, you can see that the canvas wagon cover has a plastic window sewn into it.
Continuity mistake: Grace Snider Edwards was played by two different people with no explanation. Bonnie Bartlett played her all along, but Corinne Camacho played her for one episode only.
Revealing mistake: When Carrie (played by twins) falls down in the opening sequence, it appears that she gets back up and continues running. In reality, after falling, the other twin gets up and continues. If you look closely enough, you can see that when getting up, Carrie is slightly closer towards the camera than when the first twin fell.
Factual error: Aeroplane trails are in the sky throughout several episodes. This wouldn't have been possible in the time the show is set.