After the mill closes, Charles is unable to pay off his debt at the mercantile. Mr. Hanson is forced to close the mill after one of his big customers declares bankruptcy. This was after Hanson had already shipped them a bunch of lumber. Charles had been expecting two months worth of wages before Hanson was forced to close down. Charles must taken on several jobs at the same time. Mary gets a job to help the family, while Laura does the chores at home. When the bill finally gets paid, Nels tells Charles that he thinks Charles is the richest man in Walnut Grove, since he has a very loving family.

After Julia Sanderson's death, her three children stay with Grace, with help from Mr. Edwards. When Charles is unable to find someone to adopt all three children, he has to make the difficult decision to place them in separate homes. At the very last minute, Mr. Edwards makes a monumental decision: he marries Grace - and they take on all three children.

A widowed mother named Julia Sanderson (Patricia Neal) learns she has a terminal illness and, with no close relatives to care for her three children, John Jr., Carl and Alicia, she gets Charles to promise to find the children a new home after she dies. Meanwhile, Laura and Mary rescue some abandoned puppies, and the relationship between Mr. Edwards and Grace Snider begins to blossom.

Charles and Hansen build a bank in Walnut Grove. The banker is Mr. Sprague, a cold and heartless man. Laura becomes friends with Mr. Sprague without knowing who he really was. Mr. Sprague believes that Charles sent Laura to him to try to persuade Mr. Sprague to give a loan to Mr. Ingalls.

Charles, Mr. Edwards, and two other men take a job that involves handling and transporting explosives. They must deal with many things along the road, including prejudice.

Mary is beginning to do worse in school because she has a hard time reading the blackboard. When Mary first gets her new glasses, she really likes them. The other school children begin to tease her. She purposely loses her glasses, until she realizes that her teacher, who wears glasses, has a boyfriend.

The Olesons get themselves invited onto the Ingalls family campout, after Nellie complains that it will give Laura and Mary an advantage for the school holiday project of leaf-collecting. The two men bond while fishing and their wives try to improve their relationship, but the children continue to clash. However, when Nellie falls into a river, her later false account of what happened brings out the same Mrs. Oleson. Back at the school, the result of the leaves project gives some satisfaction to Laura and Mary.

Charles and his girls go on a trip, while Caroline stays home. Just before they leave, she gets a scratch on her leg by a rusty nail. At first, everything seems OK. However, as time progresses, she gets weaker and more ill.

When Miss Beadle can no longer handle the older students' bullying, she is fired. Her mean-spirited succecssor immediately clashes with Laura, and unfairly blames her for several incidents in the classroom.

After a tornado ruins his crop, Charles decides to sell the land and return to the Big Woods of Wisconsin without consulting his family.

Laura goes into a haunted house when Nellie dares her to do it. She becomes a friend of the old man that lives there, Mr. Pike. She finds out that he is waiting for his wife to return. After Laura learns that Mrs. Pike died years ago, she helps Mr. Pike cope with the death of his wife.

Laura and Nellie are rivals for the affections of a classmate's heart. The two polar opposites are after Jason, the new kid at school who is into inventions. Both of them have crushes on Jason, but Jason - who is into inventions and electricity - only has feelings for Laura...

Charles takes a job refinishing woodwork for Thurman in exchange for a nice set of china to give to Caroline. Widow Thurman was a lovely, young lady. To keep his secret, Charles had to lie. After he tells the girls and Caroline different stories, everyone suspects that Charles is having an affair.

Mary is excited when she has the chance to participate in a state-wide math competition. The problem is that Charles can't afford to have her go.

The school children have saved up some money to buy the Reverend a birthday present. They give the money to Mary, who is in charge of buying the present. Laura convinces Mary to buy something that they could sell to people with the hope that they could buy Reverend Alden a better gift. The plan backfires.

John is a lot more interested in books than farming or hunting. Mr. Edwards tries to make him different and buys him a gun for his birthday.

The Independence Day celebration in Walnut Grove is threatened when taxes are increased. A Russian immigrant shows the people why America is a great place. Even though the immigrant lost his land since he couldn't pay his taxes, he was happy to be in America. He considered it to be the best place to live in the world.

The son of Mrs. Whipple returns to Walnut Grove after serving in the Civil War. To forget his painful past, he takes morphine, which he becomes addicted to.

While fishing in a stream, Laura and a friend stumble upon "gold". They spend several weeks trying to pick up all of the gold. When they bring it to the bank, they learn that it is only fool's gold.

Mary, Laura, and Mr. Edwards' adopted son, Carl, go along with Charles and Mr. Edwards to a train station. The three children wander into the caboose. The caboose then begins to move backwards, going faster and faster. Another train is coming the opposite direction...

Laura and Grace Snider both need dates for the annual Spring Dance, but those they have their eyes on seem not to be interested. Caroline shares with them a 'womanly wile' she used on Charles to get his attention, but when Laura and Grace try it the consequences are not what they had hoped for. Then Charles reminds Caroline of what actually happened when she tried it on him, and she changes her advice to Laura and Grace, with a happier outcome.

It's time for baseball! After losing badly last year, Walnut Grove expects to win with their star pitcher, Mr. Mumford. People in Walnut Grove are so confident that they are going to win, they place bets on the game. However, Mr. Mumford's wife won't let her husband play because of the gambling. Caroline convinces Mr. Mumford's wife to let her husband play on the condition that any money made from the game goes to the church.