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.

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.

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.

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.

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.

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

Mary and John have fallen deeply in love and want to get married, but John has a problem. He must decide if he will accept a scholarship and go to college or stay with Mary. At first Mary doesn't want him to go until she and John both realize that he must take the scholarship to try to make his dreams of becoming a writer a reality.

After going to Chicago for the first time, Charles and Mary are very disappointed in what life in the city is really like.