After catching Bart writing his name in fresh cement, Marge lectures Bart on having more respect for Springfield.
Bart soon wanders around the town, when he decides to join up with Milhouse, to get more lemons for a lemonade stand.
They make their way to a lemon tree near the Springfield/Shelbyville border, where a group of kids from Shelbyville, engage in a verbal assault, that the Springfield kids eventually win.
In the aftermath of the win, Grandpa Simpson shows up, and relays the story about the lemon tree, claiming its planting dates back to the founding of Springfield.