This article studies the situation in church‑state relations in the United States in the late 1940s — early 1950s. The Supreme Court’s decisions in the Everson (1947), McCollum (1948) and Zorach (1952) cases concerned the majority of U. S. religious bodies. These decisions provoked debates on the issues of the secularization of American society and cooperation between church and state in various fields. Interpretation of the Establishment Clause of the First Amendment was an important subject of the polemics too. In its analysis of the debate, the article pays special attention to the attitude of Roman Catholic and Protestant leaders toward the issue, as well as to the disputes between and inside churches.