Answer:
They are feuding families
Explanation:
The Capulets and the Montagues in Romeo and Juliet are two families that are enemies. They apparently have an "ancient grudge" that is most likely irrational.
The Cunningham boys were troublemaking teenagers who were arrested with Arthur "Boo" Radley. Boo was taken home and locked away from the world by his father but the Cunninghams were sentenced to attend a state juvenile hall of the 1930s. The irony here is that the school actually gave them great education and one of the Cunninghams went to college to become an engineer.
Hope this helps =]
