Who are the cunninghams and the Ewells? What makes them different?

Atticus knew Mr. Cunningham had honour and respect. Despite being racist, Atticus felt he could get past the hate and appeal to Cunningham's humanity. Bob Ewell was pretty much set in his twisted ways. Unlike the Cunninghams, Bob Ewell had no personal or public sense of honour.

The Ewells were trashy and we're not respected by the people of Maycomb, but the Cunninghams were respected and honored by the people of Maycomb. Both families were poor but each one behaved and treated people differently resulting in the division of respect towards each family.