How come Congress can have prayer before each session and schools can ?
The prayer at the beginning of each congressional day is not mandatory. The schools cannot require prayer. People are free to pray on their own, just not as a state-sponsored activity. There were gangs in the 30s and 40s, larger and more dangerous (can you say Murder, Inc.?). And plenty of teenagers got pregnant; you just didn’t see them, as they were sent away in shame. I doubt that the school reading from the Bible and the pledge were what affected society.