The First Amendment Center is one of the premiere organizations for documenting understanding challenges to religious liberty in the United States. Here is excerpt from their website… 

Our blueprint for personal freedom and the hallmark of an open society, the First Amendment protects freedom of speech, press, religion, assembly and petition. Without the First Amendment, religious minorities could be persecuted, the government might well establish a national religion, protesters could be silenced, the press could not criticize government, and citizens could not mobilize for social change.

The First Amendment Center works to preserve and protect First Amendment freedoms through information and education. The center serves as a forum for the study and exploration of free-expression issues, including freedom of speech, of the press and of religion, and the rights to assemble and to petition the government. To view the latest information about religious liberty, particularly in the schools please visit www.firstamendmentcenter.org