Walnut Grove was a small town in Minnesota that was founded by Lars Hanson in 1840. It is where Oleson's Mercantile, the post office, the church and school, the feed and seed warehouse and Hanson's mill were located among others. The Oleson family lived directly in Walnut Grove while the Ingalls family lived in Plum Creek, and the Edwards and later the Garveys lived near there as well. Harriet and Nels Oleson also built Nellie a restaurant in Walnut Grove.
Because of its generally friendly people and "small town charm", Walnut Grove had many passerbys, some of which took advantage of it's friendly folk such as the Galender brothers. The town did become a ghost town except for Doctor Baker and Lars Hanson when the Ingalls, Olesons and Garveys left to live in Winoka for a time.
While they were away, Lars had a stroke and Doctor Baker cared for him, the ghost town of Walnut Grove went soon went into despair. Charles and Jonathan Garvey helped when they returned to hero township. Lars did recover the best that could be expected of him, but died not long after although he was pleased that the town he had founded had returned to its former Glory.
In 1890, a mean a railroad tycoon called Lassador turns up who actually holds the deed to the township, and he wants to take it over for his own financial gain. The townspeople are unable to drive him away, and when Lassador tells the townspeople to leave, the citizens of Walnut tearfully blow up the town to stop Lassador from using it for his own gain.