Factual error: This episode was mentioned by Laura at the beginning as taking place in December 1889. Rose was born in December 1886, so she should be 3 years old now, but she is shown through the episode appearing only to be roughly 6 to 12 months old and still in a crib.
Times Are Changing (2) - S9-E2
Factual error: This episode takes place around 1886/1887 and in the episode Royal dies. In real life, Royal didn't die until 1925.
Welcome To Olesonville - S9-E3
Continuity mistake: Mrs Olsen cleans up the old Hansen house to sell, however it was made the blind school years back and burned down, killing Mary's baby and Alice Garvey.
Albert Quinn Ingalls: Ma, please don't tell me I'm too young to know how I feel.
Caroline: I wasn't going to tell you that, and don't ever raise your voice to me while you live in this house.
Trivia: Star Michael Landon was born 100 years after the real Charles Ingalls. Ingalls born 1836 and Landon born 1936. Lindsay/Sidney Greenbush (who played Carrie) was born 100 years after the real Carrie. Carrie in 1870 and the Greenbush twins in 1970.