On November 6, 1991, the case of Lee v. Weisman was argued before the United Staters Supreme Court. Daniel Weisman sued his daughter’s public school to bar them from inviting clergy to offer invocation and benediction prayers at her graduation. Weisman claimed that the practice violated the Establishment Clause of the First Amendment. The Court ruled (in a 5 -4 decision) in his favor.
Justice Kennedy, who authored the majority opinion, explained– “The sole question presented is whether a religious exercise may be conducted at a graduation ceremony in circumstances where, as we have found, young graduates who object are induced to conform. No holding by this Court suggests that a school can persuade or compel a student to participate in a religious exercise. That is being done here, and it is forbidden by the Establishment Clause of the First Amendment.” You can read the entire decision at https://goo.gl/CAZJWF.