It's a complicated problem that won't be solved with one solution. It needs several solutions implemented one at a time to determine what does and doesn't work. One idea that I had was ethics and philosophy courses being required for high school freshmen. Young people should be encouraged to think about morality in a classroom setting. Just thinking about morality encourages people to be more considerate of one another (at least in my opinion).
The issue that would develop with a required ethics course would be that the state cannot completely prescribe morals. Religious freedom requires a certain degree of autonomy there, as do political impartiality requirements. Also, any quality course of philosophy is going to also expose students to thinkers like Robert Wolff, who believe that the individual defines morality. I don't know when you last interacted with freshmen, but I don't think most of them are mature enough, or have seen enough practical applications of philosophy in other subjects to have a philosophy class be successful. Finally, national legislation of education requirements can be both controversial and difficult to pass/implement.
Yeah, I'm aware of the issues with implementation. It doesn't necessarily have to be required by the government. Not sure why you're talking about the state prescribing morals. Ethics courses wouldn't do that; they would encourage people to think about morality, which is a powerful way of developing a moral compass. I don't see a problem with juniors or seniors learning about Robert Wolff; moral compasses should be as diverse as music preferences, and like i said before, thinking about morality rationally cultivates more considerate behavior in my experience. Obviously this is just my opinion and I could be completely wrong. I think you're probably right about freshmen being too immature. Obviously it isn't set in stone; juniors and seniors could probably handle it. I'm taking an ethics course at the moment and it mostly revolves around understanding concepts proposed by Kant, Mill, and other philosophers. It has nothing to do with coercing people into certain moral frameworks.