The events surrounding tinker v. des moines involved with school, so why did the first amendment apply

They fall within their first amendment rights because the Tinkers wore black bands around their arms to protest the Vietnam war. The school punished them for this. The supreme court declared that the school has no right to punish them since they have a first amendment guaranteed right to free speech and to protest the war if they want to.

In the midwest because it has more moderate climate than the north or south west which makes farming far easier.