A more thorough explanation:

School District of Abington Township, Pennsylvania v. Schempp (1963) is a U.S. Supreme Court case that ruled that mandatory religious activities in public schools, such as Bible readings and reciting the Lord's Prayer, violate the Establishment Clause of the First Amendment. This means that public schools cannot force students to participate in religious activities as part of their curriculum.

For example, in this case, two families sued their school district because their children were required to read from the Bible and recite the Lord's Prayer every day in school. The Supreme Court ruled that this was unconstitutional because it violated the Establishment Clause of the First Amendment.

The Establishment Clause prohibits the government from establishing or promoting any religion. This means that the government cannot favor one religion over another or force people to participate in religious activities. The Court ruled that the school district's argument that the readings fostered good morals was not enough to justify the religious nature of the activities.

This case is still important today because it sets a precedent for the separation of church and state in public schools. Public schools must remain neutral when it comes to religion and cannot promote or favor any particular religion.