Why was Saint John the apostle canonized?
Saint John the apostle was not canonized. Canonization didn't come around till after his death. John was a martyr for his faith in Christ.
John Bosco began educating young street boys in Turin, Italy, to distract them from a life of crime and give them a good basic knowledge of their faith. He also taught them skills for various jobs and helped them find gainful employment. He went on to form the Salesians of John Bosco which founded similar schools around the world.