A selection of Crosses used by a variety of Christian groups.

European settlement in North and South America assumed, early on, a religious policy of territorialism. When this proved difficult to enforce, the related strategy was tolerance, in which a dominant group permitted certain other groups to exist in its territory, but these "tolerated" groups often endured various restrictions and had to pay taxes to support the "official" church. Tolerance proved impractical in many parts of North America because it was difficult to enforce. Pluralism therefore developed, sometimes by default and sometimes on purpose. Leaders such as Roger Williams and William Penn had suffered persecution and strove to make religious freedom guaranteed by law. Pluralism had practical advantages: it was good for trade and it attracted settlers. Some colonial and state laws experimented with forms of pluralism long before the constitutional settlement ensured that the U.S. would have no "established" national church. An important aspect of religious pluralism in the United States is "denominationalism," in which Christian groups mutually acknowledge each other as valid expressions, or "denominations," of Christianity; all may cooperate or compete as they choose.