and inner-suburban neighborhoods that, absent immigration, would have witnessed dramatic population decline (Foner, 2013; Singer, 2004). As the panel noted above, both the foreign-born and the U.S.-born are very likely to be religiously affiliated (80% and 77% respectively), and the proportion of religiously unaffiliated is growing at a faster pace among the native-born than among immigrants (Pew Research Center, 2015). Nationwide, almost a quarter of the Catholics in the United States are foreign-born, as are nearly two-fifths of the Greek and Russian Orthodox; only 5-7 percent of Protestants, mainline and evangelical, are foreign-born (Pew Forum on Religion and Public Life, 2008). Although secularism appears to be increasing for both groups, the stronger religiosity of the foreign-born means that immigrants may play an even larger role in sustaining religious organizations in the United States in the future.

As for the incorporation of non-Christian religions into the American mainstream, it is unclear whether history will repeat itself. When Catholic and Jewish immigrants arrived from Europe in the past, Protestant denominations were more or less “established” and they dominated the public square. Those earlier immigrants experienced virulent anti-Catholic nativism and anti-Semitism (Higham, 1955). By the mid-20th century, however, Jews and Catholics had been incorporated into the system of American pluralism and Americans had come to think in terms of a tripartite perspective—Protestant, Catholic, and Jew. The very transformation of the United States into a “Judeo-Christian” nation and the decrease in religious affiliation among the native-born has meant that post-1965 immigrants enter a more religiously open society than their predecessors did 150 years ago (Pew Research Center, 2015; Alba and Foner, 2015).

An important question is whether the new religions, and Islam in particular, will eventually attain the charter status now occupied by Protestanism, Catholicism, and Judaism. It is too early to tell. The ongoing controversies over zoning for mosques near Ground Zero in New York City and in localities across the country indicates that 9/11 continues to strongly influence Americans’ perception of Islam as an existential threat and Americans’ reception of Muslims in their communities (Cesari, 2013; Goodstein, 2010). Despite pockets of opposition, however, more than 40 percent of the mosques in the United States have been built just since 2000 (Pew Research Center, 2012). Although it took more than a century, the United States was able to overcome its fear of the “Catholic menace” in the past. This history offers hope that the nation may be able to do so with regard to Islam as well. Perhaps as the historian Gary Gerstle (2015) notes, we will be talking about America as an Abrahamic civilization, a phrase joining Muslims with Jews and Christians. We are at present a long way from that formulation of American national identity, but no further than America once was from the Judeo-Christian one.”