The 1940 decision in Cantwell v. Connecticut was the first Supreme Court decision to apply the First Amendment's religious protections to the states. The case focusing on the so-called Free Exercise Clause. Everson followed in 1947 and was the first decision that incorporated the Establishment Clause. Numerous state cases followed disentangling the church from public schools, most notably the 1951 New Mexico case of Zellers v. Huff.Pfeffer, Leo (1967) Church, state, and freedom Beacon Press, Boston, Massachusetts, pages 545-549MacDougall, Curtis Daniel (1952) Understanding public opinion: A guide for newspapermen and newspaper readers Macmillan, New York, page 532Holscher, Kathleen A. (2008) Habits in the classroom: A court case regarding Catholic sisters in New Mexico Doctoral Dissertation, Department of Religion, Princeton University, page iii, Abstract and Introduction from Scribd
