Violence, either real or threatened, is a part of everyday life for the Joads. Are they violent among themselves? Is their violence premeditated? Does it achieve its goal? Find examples of where their violence is justified or unjustified.

Yes, there is violence but seldom among the sharecroppers themselves. Most all the violence takes place when the companies hire union breakers to intimidate the workforce. You are correct that the issues surrounding Casey and Tom make up the bulk of violence. The union busters cause a stir at the dance (at the government camp) but that is quickly quietened. I think for the most part the violence inflicted on these people was effective. The sharecroppers had no power to fight back with. They were intimidated and largely worked for what they were given. Both Tom and Casey tried to be peaceful. I would imagine that when their life is being immediately threatened, fighting back is their only choice.