Factual error: Albert has a band-aid on his left hand. Band-aids weren't invented until 1920.
Little House on the Prairie (1974)
1 mistake in A Promise To Keep - chronological order
Laura: I wanted to clean the blackboards extra good today, to make up for being late.
Mary Ingalls Kendall: And talking in class?
Laura: I was not talking.
Mary Ingalls Kendall: You were, too.
Laura: Was not! Nellie was talking and I was answering.
Trivia: Peter Billingsley of "A Christmas Story" plays Gideon in this episode. This was his television debut at age 11.