the wall of seperation between church and state is best found in what clause of the constitution
Separation of church and state in the United States The first amendment to the US Constitution states "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof" The two parts, known as the "establishment clause" and the "free exercise clause" respectively, form the textual basis for the Supreme Court's interpretations of the "separation of church and state" doctrine.[37] Three central concepts were derived from the 1st Amendment which became America's doctrine for church-state separation: no coercion in religious matters, no expectation to support a religion against one's will, and religious liberty encompasses all religions. In sum, citizens are free to embrace or reject a faith, any support for religion - financial or physical - must be voluntary, and all religions are equal in the eyes of the law with no special preference or favoritism.[38]
Establishment Clause The Establishment Clause is a limitation placed upon the United States Congress preventing it from passing legislation respecting an establishment of religion. The second half of the Establishment Clause inherently prohibits the government from preferring any one religion over another. While the Establishment Clause does prohibit Congress from preferring or elevating one religion over another, it does not prohibit the government's entry into the religious domain to make accommodations for religious observances and practices in order to achieve the purposes of the Free Exercise Clause.