An Aesop: It's not the size of the dog, but what's inside and his actions that matter. And being different than the norm is no reason to discriminate, let alone ostracize others.
Aw, Look! They Really Do Love Each Other: A rare moment between Nancy and the Oleson men: After she falls into the pit while running from Willie, who had pushed aside the boards covering the hole, he's visibly crestfallen as they try to rescue her and relieved when she's rescued unharmed, and Nels is the first one to pull her into a hug, even though she's covered in dirt.
Death by Childbirth: Lou's wife dies after giving birth to their daughter, and asks him to find a better job for her sake before perishing, which is what motivates him to try and find a job at the Walnut Grove bank.
Foreshadowing: Nancy snatches a letter for Willie which is said to be from a girlfriend. In the penultimate episode, Willie is shown to have one, Rachel Brown, whom he plans to marry after they finish school.
Heel–Face Turn: After Lou saves Nancy's life, Harriet not only profusely apologizes for her past treatment of him, but calls off Lou's impending trial for stealing food from the Mercantile (after his job offer at the bank was rescinded, leaving him with no source of income) and talks to Mr. Anderson at the bank to get Lou's promised position back.
My God, What Have I Done?: Harriet's realization after the man she'd ostracized for his dwarfism and led to stealing saved Nancy's life
Series Continuity Error: Mrs. Oleson claims she never saw a "midget" before, even though there were a few at the Circus in Season 6's Anabelle, including one played by Lou's actor.
